diff options
| -rw-r--r-- | src/liblzma/common/auto_decoder.c | 87 |
1 files changed, 71 insertions, 16 deletions
diff --git a/src/liblzma/common/auto_decoder.c b/src/liblzma/common/auto_decoder.c index 5fcdf168..469245d4 100644 --- a/src/liblzma/common/auto_decoder.c +++ b/src/liblzma/common/auto_decoder.c @@ -22,10 +22,17 @@ struct lzma_coder_s { + /// Stream decoder or LZMA_Alone decoder lzma_next_coder next; + uint64_t memlimit; uint32_t flags; - bool initialized; + + enum { + SEQ_INIT, + SEQ_CODE, + SEQ_FINISH, + } sequence; }; @@ -35,28 +42,67 @@ auto_decode(lzma_coder *coder, lzma_allocator *allocator, size_t in_size, uint8_t *restrict out, size_t *restrict out_pos, size_t out_size, lzma_action action) { - if (!coder->initialized) { + switch (coder->sequence) { + case SEQ_INIT: if (*in_pos >= in_size) return LZMA_OK; - lzma_ret ret; + // Update the sequence now, because we want to continue from + // SEQ_CODE even if we return some LZMA_*_CHECK. + coder->sequence = SEQ_CODE; - if (in[*in_pos] == 0xFF) - ret = lzma_stream_decoder_init( + // Detect the file format. For now this is simple, since if + // it doesn't start with 0xFF (the first magic byte of the + // new format), it has to be LZMA_Alone, or something that + // we don't support at all. + if (in[*in_pos] == 0xFF) { + return_if_error(lzma_stream_decoder_init( &coder->next, allocator, - coder->memlimit, coder->flags); - else - ret = lzma_alone_decoder_init(&coder->next, - allocator, coder->memlimit); - - if (ret != LZMA_OK) + coder->memlimit, coder->flags)); + } else { + return_if_error(lzma_alone_decoder_init(&coder->next, + allocator, coder->memlimit)); + + // If the application wants a warning about missing + // integrity check or about the check in general, we + // need to handle it here, because LZMA_Alone decoder + // doesn't accept any flags. + if (coder->flags & LZMA_WARN_NO_CHECK) + return LZMA_NO_CHECK; + + if (coder->flags & LZMA_TELL_CHECK) + return LZMA_SEE_CHECK; + } + + // Fall through + + case SEQ_CODE: { + const lzma_ret ret = coder->next.code( + coder->next.coder, allocator, + in, in_pos, in_size, + out, out_pos, out_size, action); + if (ret != LZMA_STREAM_END + || (coder->flags & LZMA_CONCATENATED) == 0) return ret; - coder->initialized = true; + coder->sequence = SEQ_FINISH; + + // Fall through + + case SEQ_FINISH: + // When LZMA_DECODE_CONCATENATED was used and we were decoding + // LZMA_Alone file, we need to check check that there is no + // trailing garbage and wait for LZMA_FINISH. + if (*in_pos < in_size) + return LZMA_DATA_ERROR; + + return action == LZMA_FINISH ? LZMA_STREAM_END : LZMA_OK; } - return coder->next.code(coder->next.coder, allocator, - in, in_pos, in_size, out, out_pos, out_size, action); + default: + assert(0); + return LZMA_PROG_ERROR; + } } @@ -69,6 +115,15 @@ auto_decoder_end(lzma_coder *coder, lzma_allocator *allocator) } +static lzma_check +auto_decoder_see_check(const lzma_coder *coder) +{ + // It is LZMA_Alone if see_check is NULL. + return coder->next.see_check == NULL ? LZMA_CHECK_NONE + : coder->next.see_check(coder->next.coder); +} + + static lzma_ret auto_decoder_init(lzma_next_coder *next, lzma_allocator *allocator, uint64_t memlimit, uint32_t flags) @@ -85,12 +140,13 @@ auto_decoder_init(lzma_next_coder *next, lzma_allocator *allocator, next->code = &auto_decode; next->end = &auto_decoder_end; + next->see_check = &auto_decoder_see_check; next->coder->next = LZMA_NEXT_CODER_INIT; } next->coder->memlimit = memlimit; next->coder->flags = flags; - next->coder->initialized = false; + next->coder->sequence = SEQ_INIT; return LZMA_OK; } @@ -102,7 +158,6 @@ lzma_auto_decoder(lzma_stream *strm, uint64_t memlimit, uint32_t flags) lzma_next_strm_init(auto_decoder_init, strm, memlimit, flags); strm->internal->supported_actions[LZMA_RUN] = true; -// strm->internal->supported_actions[LZMA_SYNC_FLUSH] = true; FIXME strm->internal->supported_actions[LZMA_FINISH] = true; return LZMA_OK; |