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// SPDX-License-Identifier: GPL-2.0+
/*
* erofs-utils/lib/decompress.c
*
* Copyright (C), 2008-2020, OPPO Mobile Comm Corp., Ltd.
* Created by Huang Jianan <huangjianan@oppo.com>
*/
#include <stdlib.h>
#include "erofs/decompress.h"
#include "erofs/err.h"
#ifdef LZ4_ENABLED
#include <lz4.h>
static int z_erofs_decompress_lz4(struct z_erofs_decompress_req *rq)
{
int ret = 0;
char *dest = rq->out;
char *src = rq->in;
char *buff = NULL;
bool support_0padding = false;
unsigned int inputmargin = 0;
if (erofs_sb_has_lz4_0padding()) {
support_0padding = true;
while (!src[inputmargin & ~PAGE_MASK])
if (!(++inputmargin & ~PAGE_MASK))
break;
if (inputmargin >= rq->inputsize)
return -EIO;
}
if (rq->decodedskip) {
buff = malloc(rq->decodedlength);
if (!buff)
return -ENOMEM;
dest = buff;
}
if (rq->partial_decoding || !support_0padding)
ret = LZ4_decompress_safe_partial(src + inputmargin, dest,
rq->inputsize - inputmargin,
rq->decodedlength, rq->decodedlength);
else
ret = LZ4_decompress_safe(src + inputmargin, dest,
rq->inputsize - inputmargin,
rq->decodedlength);
if (ret != (int)rq->decodedlength) {
ret = -EIO;
goto out;
}
if (rq->decodedskip)
memcpy(rq->out, dest + rq->decodedskip,
rq->decodedlength - rq->decodedskip);
out:
if (buff)
free(buff);
return ret;
}
#endif
int z_erofs_decompress(struct z_erofs_decompress_req *rq)
{
if (rq->alg == Z_EROFS_COMPRESSION_SHIFTED) {
if (rq->inputsize != EROFS_BLKSIZ)
return -EFSCORRUPTED;
DBG_BUGON(rq->decodedlength > EROFS_BLKSIZ);
DBG_BUGON(rq->decodedlength < rq->decodedskip);
memcpy(rq->out, rq->in + rq->decodedskip,
rq->decodedlength - rq->decodedskip);
return 0;
}
#ifdef LZ4_ENABLED
if (rq->alg == Z_EROFS_COMPRESSION_LZ4)
return z_erofs_decompress_lz4(rq);
#endif
return -EOPNOTSUPP;
}