/*
 * Wrapper for decompressing LZIP-compressed kernel, initramfs, and initrd
 *
 * Copyright (C) 2016-2024 Antonio Diaz Diaz.
 *
 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
 */

#ifdef STATIC
#define PREBOOT
#include "lzip_decompress.c"
#else
#include "linux_lzip.h"
#include "linux_lunzip.h"
#include "linux_mm.h"
#endif

STATIC int INIT __lunzip(unsigned char *inbuf, long in_len,
			long (*fill)(void*, unsigned long),
			long (*flush)(void*, unsigned long),
			unsigned char *outbuf, long out_size,
			long *in_posp, long *out_posp,
			void (*error)(char *x))
{
	const int retval = lzip_decompress(inbuf, in_len, fill, flush,
					outbuf, out_size, in_posp, out_posp);
	switch (retval) {
	case 0: break;
	case LZIP_OOM_INBUF:
		error("Out of memory while allocating input buffer.");
		break;
	case LZIP_HEADER1_EOF:
		error("File ends unexpectedly at member header.");
		break;
	case LZIP_HEADER2_EOF:
		error("Truncated header in multimember file.");
		break;
	case LZIP_BAD_MAGIC1:
		error("Bad magic number (file not in lzip format).");
		break;
	case LZIP_BAD_MAGIC2:
		error("Corrupt header in multimember file.");
		break;
	case LZIP_BAD_VERSION:
		error("Version of lzip member format not supported.");
		break;
	case LZIP_BAD_DICT_SIZE:
		error("Invalid dictionary size in member header.");
		break;
	case LZIP_OOM_OUTBUF:
		error("Out of memory while allocating output buffer.");
		break;
	case LZIP_WRITE_ERROR:
		error("Write error.");
		break;
	case LZIP_BAD_DATA:
		error("LZIP-compressed data is corrupt.");
		break;
	case LZIP_DATA_EOF:
		error("LZIP-compressed data ends unexpectedly.");
		break;
	case LZIP_BAD_CRC:
		error("CRC mismatch in LZIP-compressed data.");
		break;
	default: error("Bug in the LZIP decompressor.");
	}
	return retval;
}

#ifndef PREBOOT
/* decompress_fn (see include/linux/decompress/generic.h) should have an
 * out_size argument to prevent overflowing outbuf in case of corruption
 * of the compressed data.
 */
STATIC int INIT lunzip(unsigned char *inbuf, long in_len,
			long (*fill)(void*, unsigned long),
			long (*flush)(void*, unsigned long),
			unsigned char *outbuf,
			long *in_posp,
			void (*error)(char *x))
{
	return __lunzip(inbuf, in_len, fill, flush, outbuf, LONG_MAX,
			in_posp, 0, error);
}
#else
STATIC int INIT __decompress(unsigned char *inbuf, long in_len,
			long (*fill)(void*, unsigned long),
			long (*flush)(void*, unsigned long),
			unsigned char *outbuf, long out_size,
			long *in_posp,
			void (*error)(char *x))
{
/* Some archs pass out_size = 0 (to mean unlimited size), which is unsafe
 * in case of corruption of the compressed data.
 */
	return __lunzip(inbuf, in_len - 4, fill, flush, outbuf,
			out_size ? out_size : LONG_MAX, in_posp, 0, error);
}
#endif