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path: root/src/liblzma/common/auto_decoder.c
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Diffstat (limited to 'src/liblzma/common/auto_decoder.c')
-rw-r--r--src/liblzma/common/auto_decoder.c87
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;