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
16 extern LZMA_API(lzma_ret)
lzma_raw_buffer_decode(const lzma_filter * filters,const lzma_allocator * allocator,const uint8_t * in,size_t * in_pos,size_t in_size,uint8_t * out,size_t * out_pos,size_t out_size)17 lzma_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