diff options
Diffstat (limited to 'contrib/xz/src/liblzma/subblock/subblock_decoder.c')
| -rw-r--r-- | contrib/xz/src/liblzma/subblock/subblock_decoder.c | 630 |
1 files changed, 0 insertions, 630 deletions
diff --git a/contrib/xz/src/liblzma/subblock/subblock_decoder.c b/contrib/xz/src/liblzma/subblock/subblock_decoder.c deleted file mode 100644 index e055cee..0000000 --- a/contrib/xz/src/liblzma/subblock/subblock_decoder.c +++ /dev/null @@ -1,630 +0,0 @@ -/////////////////////////////////////////////////////////////////////////////// -// -/// \file subblock_decoder.c -/// \brief Decoder of the Subblock filter -// -// Author: Lasse Collin -// -// This file has been put into the public domain. -// You can do whatever you want with this file. -// -/////////////////////////////////////////////////////////////////////////////// - -#include "subblock_decoder.h" -#include "subblock_decoder_helper.h" -#include "filter_decoder.h" - - -/// Maximum number of consecutive Subblocks with Subblock Type Padding -#define PADDING_MAX 31 - - -struct lzma_coder_s { - lzma_next_coder next; - - enum { - // These require that there is at least one input - // byte available. - SEQ_FLAGS, - SEQ_FILTER_FLAGS, - SEQ_FILTER_END, - SEQ_REPEAT_COUNT_1, - SEQ_REPEAT_COUNT_2, - SEQ_REPEAT_COUNT_3, - SEQ_REPEAT_SIZE, - SEQ_REPEAT_READ_DATA, - SEQ_SIZE_1, - SEQ_SIZE_2, - SEQ_SIZE_3, // This must be right before SEQ_DATA. - - // These don't require any input to be available. - SEQ_DATA, - SEQ_REPEAT_FAST, - SEQ_REPEAT_NORMAL, - } sequence; - - /// Number of bytes left in the current Subblock Data field. - size_t size; - - /// Number of consecutive Subblocks with Subblock Type Padding - uint32_t padding; - - /// True when .next.code() has returned LZMA_STREAM_END. - bool next_finished; - - /// True when the Subblock decoder has detected End of Payload Marker. - /// This may become true before next_finished becomes true. - bool this_finished; - - /// True if Subfilters are allowed. - bool allow_subfilters; - - /// Indicates if at least one byte of decoded output has been - /// produced after enabling Subfilter. - bool got_output_with_subfilter; - - /// Possible subfilter - lzma_next_coder subfilter; - - /// Filter Flags decoder is needed to parse the ID and Properties - /// of the subfilter. - lzma_next_coder filter_flags_decoder; - - /// The filter_flags_decoder stores its results here. - lzma_filter filter_flags; - - /// Options for the Subblock decoder helper. This is used to tell - /// the helper when it should return LZMA_STREAM_END to the subfilter. - lzma_options_subblock_helper helper; - - struct { - /// How many times buffer should be repeated - size_t count; - - /// Size of the buffer - size_t size; - - /// Position in the buffer - size_t pos; - - /// Buffer to hold the data to be repeated - uint8_t buffer[LZMA_SUBBLOCK_RLE_MAX]; - } repeat; - - /// Temporary buffer needed when the Subblock filter is not the last - /// filter in the chain. The output of the next filter is first - /// decoded into buffer[], which is then used as input for the actual - /// Subblock decoder. - struct { - size_t pos; - size_t size; - uint8_t buffer[LZMA_BUFFER_SIZE]; - } temp; -}; - - -/// Values of valid Subblock Flags -enum { - FLAG_PADDING, - FLAG_EOPM, - FLAG_DATA, - FLAG_REPEAT, - FLAG_SET_SUBFILTER, - FLAG_END_SUBFILTER, -}; - - -/// Calls the subfilter and updates coder->uncompressed_size. -static lzma_ret -subfilter_decode(lzma_coder *coder, lzma_allocator *allocator, - const uint8_t *in, size_t *in_pos, - size_t in_size, uint8_t *restrict out, - size_t *restrict out_pos, size_t out_size, lzma_action action) -{ - assert(coder->subfilter.code != NULL); - - // Call the subfilter. - const lzma_ret ret = coder->subfilter.code( - coder->subfilter.coder, allocator, - in, in_pos, in_size, out, out_pos, out_size, action); - - return ret; -} - - -static lzma_ret -decode_buffer(lzma_coder *coder, lzma_allocator *allocator, - const uint8_t *in, size_t *in_pos, - size_t in_size, uint8_t *restrict out, - size_t *restrict out_pos, size_t out_size, lzma_action action) -{ - while (*out_pos < out_size && (*in_pos < in_size - || coder->sequence >= SEQ_DATA)) - switch (coder->sequence) { - case SEQ_FLAGS: { - // Do the correct action depending on the Subblock Type. - switch (in[*in_pos] >> 4) { - case FLAG_PADDING: - // Only check that reserved bits are zero. - if (++coder->padding > PADDING_MAX - || in[*in_pos] & 0x0F) - return LZMA_DATA_ERROR; - ++*in_pos; - break; - - case FLAG_EOPM: - // There must be no Padding before EOPM. - if (coder->padding != 0) - return LZMA_DATA_ERROR; - - // Check that reserved bits are zero. - if (in[*in_pos] & 0x0F) - return LZMA_DATA_ERROR; - - // There must be no Subfilter enabled. - if (coder->subfilter.code != NULL) - return LZMA_DATA_ERROR; - - ++*in_pos; - return LZMA_STREAM_END; - - case FLAG_DATA: - // First four bits of the Subblock Data size. - coder->size = in[*in_pos] & 0x0F; - ++*in_pos; - coder->got_output_with_subfilter = true; - coder->sequence = SEQ_SIZE_1; - break; - - case FLAG_REPEAT: - // First four bits of the Repeat Count. We use - // coder->size as a temporary place for it. - coder->size = in[*in_pos] & 0x0F; - ++*in_pos; - coder->got_output_with_subfilter = true; - coder->sequence = SEQ_REPEAT_COUNT_1; - break; - - case FLAG_SET_SUBFILTER: { - if (coder->padding != 0 || (in[*in_pos] & 0x0F) - || coder->subfilter.code != NULL - || !coder->allow_subfilters) - return LZMA_DATA_ERROR; - - assert(coder->filter_flags.options == NULL); - abort(); -// return_if_error(lzma_filter_flags_decoder_init( -// &coder->filter_flags_decoder, -// allocator, &coder->filter_flags)); - - coder->got_output_with_subfilter = false; - - ++*in_pos; - coder->sequence = SEQ_FILTER_FLAGS; - break; - } - - case FLAG_END_SUBFILTER: { - if (coder->padding != 0 || (in[*in_pos] & 0x0F) - || coder->subfilter.code == NULL - || !coder->got_output_with_subfilter) - return LZMA_DATA_ERROR; - - // Tell the helper filter to indicate End of Input - // to our subfilter. - coder->helper.end_was_reached = true; - - size_t dummy = 0; - const lzma_ret ret = subfilter_decode(coder, allocator, - NULL, &dummy, 0, out, out_pos,out_size, - action); - - // If we didn't reach the end of the subfilter's output - // yet, return to the application. On the next call we - // will get to this same switch-case again, because we - // haven't updated *in_pos yet. - if (ret != LZMA_STREAM_END) - return ret; - - // Free Subfilter's memory. This is a bit debatable, - // since we could avoid some malloc()/free() calls - // if the same Subfilter gets used soon again. But - // if Subfilter isn't used again, we could leave - // a memory-hogging filter dangling until someone - // frees Subblock filter itself. - lzma_next_end(&coder->subfilter, allocator); - - // Free memory used for subfilter options. This is - // safe, because we don't support any Subfilter that - // would allow pointers in the options structure. - lzma_free(coder->filter_flags.options, allocator); - coder->filter_flags.options = NULL; - - ++*in_pos; - - break; - } - - default: - return LZMA_DATA_ERROR; - } - - break; - } - - case SEQ_FILTER_FLAGS: { - const lzma_ret ret = coder->filter_flags_decoder.code( - coder->filter_flags_decoder.coder, allocator, - in, in_pos, in_size, NULL, NULL, 0, LZMA_RUN); - if (ret != LZMA_STREAM_END) - return ret == LZMA_OPTIONS_ERROR - ? LZMA_DATA_ERROR : ret; - - // Don't free the filter_flags_decoder. It doesn't take much - // memory and we may need it again. - - // Initialize the Subfilter. Subblock and Copy filters are - // not allowed. - if (coder->filter_flags.id == LZMA_FILTER_SUBBLOCK) - return LZMA_DATA_ERROR; - - coder->helper.end_was_reached = false; - - lzma_filter filters[3] = { - { - .id = coder->filter_flags.id, - .options = coder->filter_flags.options, - }, { - .id = LZMA_FILTER_SUBBLOCK_HELPER, - .options = &coder->helper, - }, { - .id = LZMA_VLI_UNKNOWN, - .options = NULL, - } - }; - - // Optimization: We know that LZMA uses End of Payload Marker - // (not End of Input), so we can omit the helper filter. - if (filters[0].id == LZMA_FILTER_LZMA1) - filters[1].id = LZMA_VLI_UNKNOWN; - - return_if_error(lzma_raw_decoder_init( - &coder->subfilter, allocator, filters)); - - coder->sequence = SEQ_FLAGS; - break; - } - - case SEQ_FILTER_END: - // We are in the beginning of a Subblock. The next Subblock - // whose type is not Padding, must indicate end of Subfilter. - if (in[*in_pos] == (FLAG_PADDING << 4)) { - ++*in_pos; - break; - } - - if (in[*in_pos] != (FLAG_END_SUBFILTER << 4)) - return LZMA_DATA_ERROR; - - coder->sequence = SEQ_FLAGS; - break; - - case SEQ_REPEAT_COUNT_1: - case SEQ_SIZE_1: - // We use the same code to parse - // - the Size (28 bits) in Subblocks of type Data; and - // - the Repeat count (28 bits) in Subblocks of type - // Repeating Data. - coder->size |= (size_t)(in[*in_pos]) << 4; - ++*in_pos; - ++coder->sequence; - break; - - case SEQ_REPEAT_COUNT_2: - case SEQ_SIZE_2: - coder->size |= (size_t)(in[*in_pos]) << 12; - ++*in_pos; - ++coder->sequence; - break; - - case SEQ_REPEAT_COUNT_3: - case SEQ_SIZE_3: - coder->size |= (size_t)(in[*in_pos]) << 20; - ++*in_pos; - - // The real value is the stored value plus one. - ++coder->size; - - // This moves to SEQ_REPEAT_SIZE or SEQ_DATA. That's why - // SEQ_DATA must be right after SEQ_SIZE_3 in coder->sequence. - ++coder->sequence; - break; - - case SEQ_REPEAT_SIZE: - // Move the Repeat Count to the correct variable and parse - // the Size of the Data to be repeated. - coder->repeat.count = coder->size; - coder->repeat.size = (size_t)(in[*in_pos]) + 1; - coder->repeat.pos = 0; - - // The size of the Data field must be bigger than the number - // of Padding bytes before this Subblock. - if (coder->repeat.size <= coder->padding) - return LZMA_DATA_ERROR; - - ++*in_pos; - coder->padding = 0; - coder->sequence = SEQ_REPEAT_READ_DATA; - break; - - case SEQ_REPEAT_READ_DATA: { - // Fill coder->repeat.buffer[]. - const size_t in_avail = in_size - *in_pos; - const size_t out_avail - = coder->repeat.size - coder->repeat.pos; - const size_t copy_size = MIN(in_avail, out_avail); - - memcpy(coder->repeat.buffer + coder->repeat.pos, - in + *in_pos, copy_size); - *in_pos += copy_size; - coder->repeat.pos += copy_size; - - if (coder->repeat.pos == coder->repeat.size) { - coder->repeat.pos = 0; - - if (coder->repeat.size == 1 - && coder->subfilter.code == NULL) - coder->sequence = SEQ_REPEAT_FAST; - else - coder->sequence = SEQ_REPEAT_NORMAL; - } - - break; - } - - case SEQ_DATA: { - // The size of the Data field must be bigger than the number - // of Padding bytes before this Subblock. - assert(coder->size > 0); - if (coder->size <= coder->padding) - return LZMA_DATA_ERROR; - - coder->padding = 0; - - // Limit the amount of input to match the available - // Subblock Data size. - size_t in_limit; - if (in_size - *in_pos > coder->size) - in_limit = *in_pos + coder->size; - else - in_limit = in_size; - - if (coder->subfilter.code == NULL) { - const size_t copy_size = lzma_bufcpy( - in, in_pos, in_limit, - out, out_pos, out_size); - - coder->size -= copy_size; - } else { - const size_t in_start = *in_pos; - const lzma_ret ret = subfilter_decode( - coder, allocator, - in, in_pos, in_limit, - out, out_pos, out_size, - action); - - // Update the number of unprocessed bytes left in - // this Subblock. This assert() is true because - // in_limit prevents *in_pos getting too big. - assert(*in_pos - in_start <= coder->size); - coder->size -= *in_pos - in_start; - - if (ret == LZMA_STREAM_END) { - // End of Subfilter can occur only at - // a Subblock boundary. - if (coder->size != 0) - return LZMA_DATA_ERROR; - - // We need a Subblock with Unset - // Subfilter before more data. - coder->sequence = SEQ_FILTER_END; - break; - } - - if (ret != LZMA_OK) - return ret; - } - - // If we couldn't process the whole Subblock Data yet, return. - if (coder->size > 0) - return LZMA_OK; - - coder->sequence = SEQ_FLAGS; - break; - } - - case SEQ_REPEAT_FAST: { - // Optimization for cases when there is only one byte to - // repeat and no Subfilter. - const size_t out_avail = out_size - *out_pos; - const size_t copy_size = MIN(coder->repeat.count, out_avail); - - memset(out + *out_pos, coder->repeat.buffer[0], copy_size); - - *out_pos += copy_size; - coder->repeat.count -= copy_size; - - if (coder->repeat.count != 0) - return LZMA_OK; - - coder->sequence = SEQ_FLAGS; - break; - } - - case SEQ_REPEAT_NORMAL: - do { - // Cycle the repeat buffer if needed. - if (coder->repeat.pos == coder->repeat.size) { - if (--coder->repeat.count == 0) { - coder->sequence = SEQ_FLAGS; - break; - } - - coder->repeat.pos = 0; - } - - if (coder->subfilter.code == NULL) { - lzma_bufcpy(coder->repeat.buffer, - &coder->repeat.pos, - coder->repeat.size, - out, out_pos, out_size); - } else { - const lzma_ret ret = subfilter_decode( - coder, allocator, - coder->repeat.buffer, - &coder->repeat.pos, - coder->repeat.size, - out, out_pos, out_size, - action); - - if (ret == LZMA_STREAM_END) { - // End of Subfilter can occur only at - // a Subblock boundary. - if (coder->repeat.pos - != coder->repeat.size - || --coder->repeat - .count != 0) - return LZMA_DATA_ERROR; - - // We need a Subblock with Unset - // Subfilter before more data. - coder->sequence = SEQ_FILTER_END; - break; - - } else if (ret != LZMA_OK) { - return ret; - } - } - } while (*out_pos < out_size); - - break; - - default: - return LZMA_PROG_ERROR; - } - - return LZMA_OK; -} - - -static lzma_ret -subblock_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) -{ - if (coder->next.code == NULL) - return decode_buffer(coder, allocator, in, in_pos, in_size, - out, out_pos, out_size, action); - - while (*out_pos < out_size) { - if (!coder->next_finished - && coder->temp.pos == coder->temp.size) { - coder->temp.pos = 0; - coder->temp.size = 0; - - const lzma_ret ret = coder->next.code( - coder->next.coder, - allocator, in, in_pos, in_size, - coder->temp.buffer, &coder->temp.size, - LZMA_BUFFER_SIZE, action); - - if (ret == LZMA_STREAM_END) - coder->next_finished = true; - else if (coder->temp.size == 0 || ret != LZMA_OK) - return ret; - } - - if (coder->this_finished) { - if (coder->temp.pos != coder->temp.size) - return LZMA_DATA_ERROR; - - if (coder->next_finished) - return LZMA_STREAM_END; - - return LZMA_OK; - } - - const lzma_ret ret = decode_buffer(coder, allocator, - coder->temp.buffer, &coder->temp.pos, - coder->temp.size, - out, out_pos, out_size, action); - - if (ret == LZMA_STREAM_END) - // The next coder in the chain hasn't finished - // yet. If the input data is valid, there - // must be no more output coming, but the - // next coder may still need a litle more - // input to detect End of Payload Marker. - coder->this_finished = true; - else if (ret != LZMA_OK) - return ret; - else if (coder->next_finished && *out_pos < out_size) - return LZMA_DATA_ERROR; - } - - return LZMA_OK; -} - - -static void -subblock_decoder_end(lzma_coder *coder, lzma_allocator *allocator) -{ - lzma_next_end(&coder->next, allocator); - lzma_next_end(&coder->subfilter, allocator); - lzma_next_end(&coder->filter_flags_decoder, allocator); - lzma_free(coder->filter_flags.options, allocator); - lzma_free(coder, allocator); - return; -} - - -extern lzma_ret -lzma_subblock_decoder_init(lzma_next_coder *next, lzma_allocator *allocator, - const lzma_filter_info *filters) -{ - if (next->coder == NULL) { - next->coder = lzma_alloc(sizeof(lzma_coder), allocator); - if (next->coder == NULL) - return LZMA_MEM_ERROR; - - next->code = &subblock_decode; - next->end = &subblock_decoder_end; - - next->coder->next = LZMA_NEXT_CODER_INIT; - next->coder->subfilter = LZMA_NEXT_CODER_INIT; - next->coder->filter_flags_decoder = LZMA_NEXT_CODER_INIT; - - } else { - lzma_next_end(&next->coder->subfilter, allocator); - lzma_free(next->coder->filter_flags.options, allocator); - } - - next->coder->filter_flags.options = NULL; - - next->coder->sequence = SEQ_FLAGS; - next->coder->padding = 0; - next->coder->next_finished = false; - next->coder->this_finished = false; - next->coder->temp.pos = 0; - next->coder->temp.size = 0; - - if (filters[0].options != NULL) - next->coder->allow_subfilters = ((lzma_options_subblock *)( - filters[0].options))->allow_subfilters; - else - next->coder->allow_subfilters = false; - - return lzma_next_filter_init( - &next->coder->next, allocator, filters + 1); -} |
