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