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-rw-r--r--src/liblzma/common/stream_decoder.c458
1 files changed, 138 insertions, 320 deletions
diff --git a/src/liblzma/common/stream_decoder.c b/src/liblzma/common/stream_decoder.c
index 56de3d9f..1bf7f1f8 100644
--- a/src/liblzma/common/stream_decoder.c
+++ b/src/liblzma/common/stream_decoder.c
@@ -18,281 +18,148 @@
///////////////////////////////////////////////////////////////////////////////
#include "stream_common.h"
+#include "stream_decoder.h"
#include "check.h"
#include "stream_flags_decoder.h"
#include "block_decoder.h"
-#include "metadata_decoder.h"
struct lzma_coder_s {
enum {
- SEQ_STREAM_HEADER_CODE,
- SEQ_BLOCK_HEADER_INIT,
- SEQ_BLOCK_HEADER_CODE,
- SEQ_METADATA_CODE,
- SEQ_DATA_CODE,
- SEQ_STREAM_TAIL_INIT,
- SEQ_STREAM_TAIL_CODE,
+ SEQ_STREAM_HEADER,
+ SEQ_BLOCK_HEADER,
+ SEQ_BLOCK,
+ SEQ_INDEX,
+ SEQ_STREAM_FOOTER,
} sequence;
- /// Position in variable-length integers and in some other things.
- size_t pos;
-
/// Block or Metadata decoder. This takes little memory and the same
/// data structure can be used to decode every Block Header, so it's
/// a good idea to have a separate lzma_next_coder structure for it.
lzma_next_coder block_decoder;
- /// Block Header decoder; this is separate
- lzma_next_coder block_header_decoder;
-
+ /// Block options decoded by the Block Header decoder and used by
+ /// the Block decoder.
lzma_options_block block_options;
- /// Information about the sizes of the Blocks
- lzma_info *info;
-
- /// Current Block in *info
- lzma_info_iter iter;
-
- /// Number of bytes not yet processed from Data Blocks in the Stream.
- /// This can be LZMA_VLI_VALUE_UNKNOWN. If it is known, it is
- /// decremented while decoding and verified to match the reality.
- lzma_vli total_left;
-
- /// Like uncompressed_left above but for uncompressed data from
- /// Data Blocks.
- lzma_vli uncompressed_left;
-
/// Stream Flags from Stream Header
- lzma_stream_flags header_flags;
-
- /// Stream Flags from Stream tail
- lzma_stream_flags tail_flags;
+ lzma_stream_flags stream_flags;
- /// Decoder for Stream Header and Stream tail. This takes very
- /// little memory and the same data structure can be used for
- /// both Header and tail, so it's a good idea to have a separate
- /// lzma_next_coder structure for it.
- lzma_next_coder flags_decoder;
+ /// Index is hashed so that it can be compared to the sizes of Blocks
+ /// with O(1) memory usage.
+ lzma_index_hash *index_hash;
- /// Temporary destination for the decoded Metadata.
- lzma_metadata metadata;
+ /// Write position in buffer[]
+ size_t buffer_pos;
- /// Pointer to application-supplied pointer where to store the list
- /// of Extra Records from the Header Metadata Block.
- lzma_extra **header_extra;
-
- /// Same as above but Footer Metadata Block
- lzma_extra **footer_extra;
+ /// Buffer to hold Stream Header, Block Header, and Stream Footer.
+ /// Block Header has biggest maximum size.
+ uint8_t buffer[LZMA_BLOCK_HEADER_SIZE_MAX];
};
static lzma_ret
-metadata_init(lzma_coder *coder, lzma_allocator *allocator)
-{
- assert(coder->metadata.index == NULL);
- assert(coder->metadata.extra == NULL);
-
- // Single-Block Streams don't have Metadata Blocks.
- if (!coder->header_flags.is_multi)
- return LZMA_DATA_ERROR;
-
- coder->block_options.total_limit = LZMA_VLI_VALUE_UNKNOWN;
-
- // Limit the Uncompressed Size of a Metadata Block. This is to
- // prevent security issues where input file would have very huge
- // Metadata.
- //
- // FIXME: Hardcoded constant is ugly. Maybe we should provide
- // some way to specify this from the application.
- coder->block_options.uncompressed_limit = LZMA_VLI_C(1) << 23;
-
- lzma_info_size size_type;
- bool want_extra;
-
- // If we haven't decoded any Data Blocks yet, this is Header
- // Metadata Block.
- if (lzma_info_index_count_get(coder->info) == 0) {
- coder->block_options.has_backward_size = false;
- coder->block_options.handle_padding = true;
- size_type = LZMA_INFO_HEADER_METADATA;
- want_extra = coder->header_extra != NULL;
- } else {
- if (lzma_info_index_finish(coder->info))
- return LZMA_DATA_ERROR;
-
- coder->block_options.has_backward_size = true;
- coder->block_options.handle_padding = false;
- size_type = LZMA_INFO_FOOTER_METADATA;
- want_extra = coder->footer_extra != NULL;
- }
-
- coder->block_options.has_uncompressed_size_in_footer = false;
- coder->block_options.total_size = lzma_info_size_get(
- coder->info, size_type);
-
- coder->sequence = SEQ_METADATA_CODE;
-
- return lzma_metadata_decoder_init(&coder->block_decoder, allocator,
- &coder->block_options, &coder->metadata, want_extra);
-}
-
-
-static lzma_ret
-data_init(lzma_coder *coder, lzma_allocator *allocator)
-{
- return_if_error(lzma_info_iter_next(&coder->iter, allocator));
-
- return_if_error(lzma_info_iter_set(
- &coder->iter, LZMA_VLI_VALUE_UNKNOWN,
- coder->block_options.uncompressed_size));
-
- coder->block_options.total_size = coder->iter.total_size;
- coder->block_options.uncompressed_size = coder->iter.uncompressed_size;
- coder->block_options.total_limit = coder->total_left;
- coder->block_options.uncompressed_limit = coder->uncompressed_left;
-
- if (coder->header_flags.is_multi) {
- coder->block_options.has_uncompressed_size_in_footer = false;
- coder->block_options.has_backward_size = false;
- coder->block_options.handle_padding = true;
- } else {
- coder->block_options.has_uncompressed_size_in_footer
- = coder->iter.uncompressed_size
- == LZMA_VLI_VALUE_UNKNOWN;
- coder->block_options.has_backward_size = true;
- coder->block_options.handle_padding = false;
- }
-
- coder->sequence = SEQ_DATA_CODE;
-
- return lzma_block_decoder_init(&coder->block_decoder, allocator,
- &coder->block_options);
-}
-
-
-static lzma_ret
stream_decode(lzma_coder *coder, lzma_allocator *allocator,
const uint8_t *restrict in, size_t *restrict in_pos,
size_t in_size, uint8_t *restrict out,
size_t *restrict out_pos, size_t out_size, lzma_action action)
{
+ // When decoding the actual Block, it may be able to produce more
+ // output even if we don't give it any new input.
while (*out_pos < out_size && (*in_pos < in_size
- || coder->sequence == SEQ_DATA_CODE))
+ || coder->sequence == SEQ_BLOCK))
switch (coder->sequence) {
- case SEQ_STREAM_HEADER_CODE: {
- const lzma_ret ret = coder->flags_decoder.code(
- coder->flags_decoder.coder,
- allocator, in, in_pos, in_size,
- NULL, NULL, 0, LZMA_RUN);
- if (ret != LZMA_STREAM_END)
- return ret;
+ case SEQ_STREAM_HEADER: {
+ // Copy the Stream Header to the internal buffer.
+ bufcpy(in, in_pos, in_size, coder->buffer, &coder->buffer_pos,
+ LZMA_STREAM_HEADER_SIZE);
+
+ // Return if we didn't get the whole Stream Header yet.
+ if (coder->buffer_pos < LZMA_STREAM_HEADER_SIZE)
+ return LZMA_OK;
+
+ coder->buffer_pos = 0;
+
+ // Decode the Stream Header.
+ return_if_error(lzma_stream_header_decode(
+ &coder->stream_flags, coder->buffer));
- coder->sequence = SEQ_BLOCK_HEADER_INIT;
+ // Copy the type of the Check so that Block Header and Block
+ // decoders see it.
+ coder->block_options.check = coder->stream_flags.check;
+
+ // Even if we return LZMA_UNSUPPORTED_CHECK below, we want
+ // to continue from Block Header decoding.
+ coder->sequence = SEQ_BLOCK_HEADER;
// Detect if the Check type is supported and give appropriate
// warning if it isn't. We don't warn every time a new Block
// is started.
- lzma_check tmp;
- if (lzma_check_init(&tmp, coder->header_flags.check))
+ if (!lzma_available_checks[coder->block_options.check])
return LZMA_UNSUPPORTED_CHECK;
break;
}
- case SEQ_BLOCK_HEADER_INIT: {
- coder->block_options.check = coder->header_flags.check;
- coder->block_options.has_crc32 = coder->header_flags.has_crc32;
+ case SEQ_BLOCK_HEADER: {
+ if (coder->buffer_pos == 0) {
+ // Detect if it's Index.
+ if (in[*in_pos] == 0x00) {
+ coder->sequence = SEQ_INDEX;
+ break;
+ }
- for (size_t i = 0;
- i < ARRAY_SIZE(coder->block_options.filters);
- ++i) {
- lzma_free(coder->block_options.filters[i].options,
- allocator);
- coder->block_options.filters[i].options = NULL;
+ // Calculate the size of the Block Header. Note that
+ // Block Header decoder wants to see this byte too
+ // so don't advance *in_pos.
+ coder->block_options.header_size
+ = lzma_block_header_size_decode(
+ in[*in_pos]);
}
- return_if_error(lzma_block_header_decoder_init(
- &coder->block_header_decoder, allocator,
- &coder->block_options));
-
- coder->sequence = SEQ_BLOCK_HEADER_CODE;
- }
-
- // Fall through
-
- case SEQ_BLOCK_HEADER_CODE: {
- lzma_ret ret = coder->block_header_decoder.code(
- coder->block_header_decoder.coder,
- allocator, in, in_pos, in_size,
- NULL, NULL, 0, LZMA_RUN);
-
- if (ret != LZMA_STREAM_END)
- return ret;
+ // Copy the Block Header to the internal buffer.
+ bufcpy(in, in_pos, in_size, coder->buffer, &coder->buffer_pos,
+ coder->block_options.header_size);
- if (coder->block_options.is_metadata)
- ret = metadata_init(coder, allocator);
- else
- ret = data_init(coder, allocator);
-
- if (ret != LZMA_OK)
- return ret;
-
- break;
- }
+ // Return if we didn't get the whole Block Header yet.
+ if (coder->buffer_pos < coder->block_options.header_size)
+ return LZMA_OK;
- case SEQ_METADATA_CODE: {
- lzma_ret ret = coder->block_decoder.code(
- coder->block_decoder.coder, allocator,
- in, in_pos, in_size, NULL, NULL, 0, LZMA_RUN);
- if (ret != LZMA_STREAM_END)
- return ret;
+ coder->buffer_pos = 0;
- const bool is_header_metadata = lzma_info_index_count_get(
- coder->info) == 0;
+ // Set up a buffer to hold the filter chain. Block Header
+ // decoder will initialize all members of this array so
+ // we don't need to do it here.
+ lzma_options_filter filters[LZMA_BLOCK_FILTERS_MAX + 1];
+ coder->block_options.filters = filters;
- if (is_header_metadata) {
- if (coder->header_extra != NULL) {
- *coder->header_extra = coder->metadata.extra;
- coder->metadata.extra = NULL;
- }
+ // Decode the Block Header.
+ return_if_error(lzma_block_header_decode(&coder->block_options,
+ allocator, coder->buffer));
- if (lzma_info_size_set(coder->info,
- LZMA_INFO_HEADER_METADATA,
- coder->block_options.total_size)
- != LZMA_OK)
- return LZMA_PROG_ERROR;
-
- coder->sequence = SEQ_BLOCK_HEADER_INIT;
- } else {
- if (coder->footer_extra != NULL) {
- *coder->footer_extra = coder->metadata.extra;
- coder->metadata.extra = NULL;
- }
+ // Initialize the Block decoder.
+ const lzma_ret ret = lzma_block_decoder_init(
+ &coder->block_decoder,
+ allocator, &coder->block_options);
- coder->sequence = SEQ_STREAM_TAIL_INIT;
- }
+ // Free the allocated filter options since they are needed
+ // only to initialize the Block decoder.
+ for (size_t i = 0; i < LZMA_BLOCK_FILTERS_MAX; ++i)
+ lzma_free(filters[i].options, allocator);
- assert(coder->metadata.extra == NULL);
+ coder->block_options.filters = NULL;
- ret = lzma_info_metadata_set(coder->info, allocator,
- &coder->metadata, is_header_metadata, true);
- if (ret != LZMA_OK)
+ // Check if Block enocoder initialization succeeded. Don't
+ // warn about unsupported check anymore since we did it
+ // earlier if it was needed.
+ if (ret != LZMA_OK && ret != LZMA_UNSUPPORTED_CHECK)
return ret;
- // Intialize coder->total_size and coder->uncompressed_size
- // from Header Metadata.
- if (is_header_metadata) {
- coder->total_left = lzma_info_size_get(
- coder->info, LZMA_INFO_TOTAL);
- coder->uncompressed_left = lzma_info_size_get(
- coder->info, LZMA_INFO_UNCOMPRESSED);
- }
-
+ coder->sequence = SEQ_BLOCK;
break;
}
- case SEQ_DATA_CODE: {
+ case SEQ_BLOCK: {
lzma_ret ret = coder->block_decoder.code(
coder->block_decoder.coder, allocator,
in, in_pos, in_size, out, out_pos, out_size,
@@ -301,62 +168,59 @@ stream_decode(lzma_coder *coder, lzma_allocator *allocator,
if (ret != LZMA_STREAM_END)
return ret;
- ret = lzma_info_iter_set(&coder->iter,
- coder->block_options.total_size,
- coder->block_options.uncompressed_size);
- if (ret != LZMA_OK)
- return ret;
-
- // These won't overflow since lzma_info_iter_set() succeeded.
- if (coder->total_left != LZMA_VLI_VALUE_UNKNOWN)
- coder->total_left -= coder->block_options.total_size;
- if (coder->uncompressed_left != LZMA_VLI_VALUE_UNKNOWN)
- coder->uncompressed_left -= coder->block_options
- .uncompressed_size;
+ // Block decoded successfully. Add the new size pair to
+ // the Index hash.
+ return_if_error(lzma_index_hash_append(coder->index_hash,
+ lzma_block_total_size_get(
+ &coder->block_options),
+ coder->block_options.uncompressed_size));
- if (!coder->header_flags.is_multi) {
- ret = lzma_info_index_finish(coder->info);
- if (ret != LZMA_OK)
- return ret;
-
- coder->sequence = SEQ_STREAM_TAIL_INIT;
- break;
- }
-
- coder->sequence = SEQ_BLOCK_HEADER_INIT;
+ coder->sequence = SEQ_BLOCK_HEADER;
break;
}
- case SEQ_STREAM_TAIL_INIT: {
- lzma_ret ret = lzma_info_index_finish(coder->info);
- if (ret != LZMA_OK)
- return ret;
-
- ret = lzma_stream_tail_decoder_init(&coder->flags_decoder,
- allocator, &coder->tail_flags);
- if (ret != LZMA_OK)
+ case SEQ_INDEX: {
+ // Decode the Index and compare it to the hash calculated
+ // from the sizes of the Blocks (if any).
+ const lzma_ret ret = lzma_index_hash_decode(coder->index_hash,
+ in, in_pos, in_size);
+ if (ret != LZMA_STREAM_END)
return ret;
- coder->sequence = SEQ_STREAM_TAIL_CODE;
+ coder->sequence = SEQ_STREAM_FOOTER;
+ break;
}
- // Fall through
+ case SEQ_STREAM_FOOTER:
+ // Copy the Stream Footer to the internal buffer.
+ bufcpy(in, in_pos, in_size, coder->buffer, &coder->buffer_pos,
+ LZMA_STREAM_HEADER_SIZE);
- case SEQ_STREAM_TAIL_CODE: {
- const lzma_ret ret = coder->flags_decoder.code(
- coder->flags_decoder.coder, allocator,
- in, in_pos, in_size, NULL, NULL, 0, LZMA_RUN);
- if (ret != LZMA_STREAM_END)
- return ret;
+ // Return if we didn't get the whole Stream Footer yet.
+ if (coder->buffer_pos < LZMA_STREAM_HEADER_SIZE)
+ return LZMA_OK;
- if (!lzma_stream_flags_is_equal(
- coder->header_flags, coder->tail_flags))
+ // Decode the Stream Footer.
+ lzma_stream_flags footer_flags;
+ return_if_error(lzma_stream_footer_decode(
+ &footer_flags, coder->buffer));
+
+ // Check that Index Size stored in the Stream Footer matches
+ // the real size of the Index field.
+ if (lzma_index_hash_size(coder->index_hash)
+ != footer_flags.backward_size)
+ return LZMA_DATA_ERROR;
+
+ // Compare that the Stream Flags fields are identical in
+ // both Stream Header and Stream Footer.
+ if (!lzma_stream_flags_equal(&coder->stream_flags,
+ &footer_flags))
return LZMA_DATA_ERROR;
return LZMA_STREAM_END;
- }
default:
+ assert(0);
return LZMA_PROG_ERROR;
}
@@ -367,23 +231,15 @@ stream_decode(lzma_coder *coder, lzma_allocator *allocator,
static void
stream_decoder_end(lzma_coder *coder, lzma_allocator *allocator)
{
- for (size_t i = 0; i < ARRAY_SIZE(coder->block_options.filters); ++i)
- lzma_free(coder->block_options.filters[i].options, allocator);
-
lzma_next_coder_end(&coder->block_decoder, allocator);
- lzma_next_coder_end(&coder->block_header_decoder, allocator);
- lzma_next_coder_end(&coder->flags_decoder, allocator);
- lzma_info_free(coder->info, allocator);
- lzma_index_free(coder->metadata.index, allocator);
- lzma_extra_free(coder->metadata.extra, allocator);
+ lzma_index_hash_end(coder->index_hash, allocator);
lzma_free(coder, allocator);
return;
}
static lzma_ret
-stream_decoder_init(lzma_next_coder *next, lzma_allocator *allocator,
- lzma_extra **header, lzma_extra **footer)
+stream_decoder_init(lzma_next_coder *next, lzma_allocator *allocator)
{
if (next->coder == NULL) {
next->coder = lzma_alloc(sizeof(lzma_coder), allocator);
@@ -394,73 +250,35 @@ stream_decoder_init(lzma_next_coder *next, lzma_allocator *allocator,
next->end = &stream_decoder_end;
next->coder->block_decoder = LZMA_NEXT_CODER_INIT;
- next->coder->block_header_decoder = LZMA_NEXT_CODER_INIT;
- next->coder->info = NULL;
- next->coder->flags_decoder = LZMA_NEXT_CODER_INIT;
- next->coder->metadata.index = NULL;
- next->coder->metadata.extra = NULL;
- } else {
- for (size_t i = 0; i < ARRAY_SIZE(
- next->coder->block_options.filters); ++i)
- lzma_free(next->coder->block_options
- .filters[i].options, allocator);
-
- lzma_index_free(next->coder->metadata.index, allocator);
- next->coder->metadata.index = NULL;
-
- lzma_extra_free(next->coder->metadata.extra, allocator);
- next->coder->metadata.extra = NULL;
+ next->coder->index_hash = NULL;
}
- for (size_t i = 0; i < ARRAY_SIZE(next->coder->block_options.filters);
- ++i)
- next->coder->block_options.filters[i].options = NULL;
-
- next->coder->info = lzma_info_init(next->coder->info, allocator);
- if (next->coder->info == NULL)
+ // Initialize the Index hash used to verify the Index.
+ next->coder->index_hash = lzma_index_hash_init(
+ next->coder->index_hash, allocator);
+ if (next->coder->index_hash == NULL)
return LZMA_MEM_ERROR;
- lzma_info_iter_begin(next->coder->info, &next->coder->iter);
-
- // Initialize Stream Header decoder.
- return_if_error(lzma_stream_header_decoder_init(
- &next->coder->flags_decoder, allocator,
- &next->coder->header_flags));
-
- // Reset the *foo_extra pointers to NULL. This way the caller knows
- // if there were no Extra Records. (We don't support appending
- // Records to Extra list.)
- if (header != NULL)
- *header = NULL;
- if (footer != NULL)
- *footer = NULL;
-
- // Reset some variables.
- next->coder->sequence = SEQ_STREAM_HEADER_CODE;
- next->coder->pos = 0;
- next->coder->uncompressed_left = LZMA_VLI_VALUE_UNKNOWN;
- next->coder->total_left = LZMA_VLI_VALUE_UNKNOWN;
- next->coder->header_extra = header;
- next->coder->footer_extra = footer;
+ // Reset the rest of the variables.
+ next->coder->sequence = SEQ_STREAM_HEADER;
+ next->coder->block_options.filters = NULL;
+ next->coder->buffer_pos = 0;
return LZMA_OK;
}
extern lzma_ret
-lzma_stream_decoder_init(lzma_next_coder *next, lzma_allocator *allocator,
- lzma_extra **header, lzma_extra **footer)
+lzma_stream_decoder_init(lzma_next_coder *next, lzma_allocator *allocator)
{
- lzma_next_coder_init(
- stream_decoder_init, next, allocator, header, footer);
+ lzma_next_coder_init0(stream_decoder_init, next, allocator);
}
extern LZMA_API lzma_ret
-lzma_stream_decoder(lzma_stream *strm,
- lzma_extra **header, lzma_extra **footer)
+lzma_stream_decoder(lzma_stream *strm)
{
- lzma_next_strm_init(strm, stream_decoder_init, header, footer);
+ lzma_next_strm_init0(strm, stream_decoder_init);
strm->internal->supported_actions[LZMA_RUN] = true;
strm->internal->supported_actions[LZMA_SYNC_FLUSH] = true;