1///////////////////////////////////////////////////////////////////////////////
2//
3/// \file       filter_buffer_decoder.c
4/// \brief      Single-call raw decoding
5//
6//  Author:     Lasse Collin
7//
8//  This file has been put into the public domain.
9//  You can do whatever you want with this file.
10//
11///////////////////////////////////////////////////////////////////////////////
12
13#include "filter_decoder.h"
14
15
16extern LZMA_API(lzma_ret)
17lzma_raw_buffer_decode(
18		const lzma_filter *filters, const lzma_allocator *allocator,
19		const uint8_t *in, size_t *in_pos, size_t in_size,
20		uint8_t *out, size_t *out_pos, size_t out_size)
21{
22	// Validate what isn't validated later in filter_common.c.
23	if (in == NULL || in_pos == NULL || *in_pos > in_size || out == NULL
24			|| out_pos == NULL || *out_pos > out_size)
25		return LZMA_PROG_ERROR;
26
27	// Initialize the decoer.
28	lzma_next_coder next = LZMA_NEXT_CODER_INIT;
29	return_if_error(lzma_raw_decoder_init(&next, allocator, filters));
30
31	// Store the positions so that we can restore them if something
32	// goes wrong.
33	const size_t in_start = *in_pos;
34	const size_t out_start = *out_pos;
35
36	// Do the actual decoding and free decoder's memory.
37	lzma_ret ret = next.code(next.coder, allocator, in, in_pos, in_size,
38			out, out_pos, out_size, LZMA_FINISH);
39
40	if (ret == LZMA_STREAM_END) {
41		ret = LZMA_OK;
42	} else {
43		if (ret == LZMA_OK) {
44			// Either the input was truncated or the
45			// output buffer was too small.
46			assert(*in_pos == in_size || *out_pos == out_size);
47
48			if (*in_pos != in_size) {
49				// Since input wasn't consumed completely,
50				// the output buffer became full and is
51				// too small.
52				ret = LZMA_BUF_ERROR;
53
54			} else if (*out_pos != out_size) {
55				// Since output didn't became full, the input
56				// has to be truncated.
57				ret = LZMA_DATA_ERROR;
58
59			} else {
60				// All the input was consumed and output
61				// buffer is full. Now we don't immediately
62				// know the reason for the error. Try
63				// decoding one more byte. If it succeeds,
64				// then the output buffer was too small. If
65				// we cannot get a new output byte, the input
66				// is truncated.
67				uint8_t tmp[1];
68				size_t tmp_pos = 0;
69				(void)next.code(next.coder, allocator,
70						in, in_pos, in_size,
71						tmp, &tmp_pos, 1, LZMA_FINISH);
72
73				if (tmp_pos == 1)
74					ret = LZMA_BUF_ERROR;
75				else
76					ret = LZMA_DATA_ERROR;
77			}
78		}
79
80		// Restore the positions.
81		*in_pos = in_start;
82		*out_pos = out_start;
83	}
84
85	lzma_next_end(&next, allocator);
86
87	return ret;
88}
89