stream_flags_decoder.c File Reference

Decodes Stream Header and Stream Footer from .xz files. More...

#include "stream_flags_common.h"

Go to the source code of this file.

Functions
static bool	stream_flags_decode (lzma_stream_flags *options, const uint8_t *in)
	LZMA_API (lzma_ret)

Detailed Description

Decodes Stream Header and Stream Footer from .xz files.

Definition in file stream_flags_decoder.c.

Function Documentation

LZMA_API()

LZMA_API

(

lzma_ret

)

Definition at line 30 of file stream_flags_decoder.c.

{
    // Magic
    if (memcmp(in, lzma_header_magic, sizeof(lzma_header_magic)) != 0)
        return LZMA_FORMAT_ERROR;
 
    // Verify the CRC32 so we can distinguish between corrupt
    // and unsupported files.
    const uint32_t crc = lzma_crc32(in + sizeof(lzma_header_magic),
            LZMA_STREAM_FLAGS_SIZE, 0);
    if (crc != read32le(in + sizeof(lzma_header_magic)
            + LZMA_STREAM_FLAGS_SIZE))
        return LZMA_DATA_ERROR;
 
    // Stream Flags
    if (stream_flags_decode(options, in + sizeof(lzma_header_magic)))
        return LZMA_OPTIONS_ERROR;
 
    // Set Backward Size to indicate unknown value. That way
    // lzma_stream_flags_compare() can be used to compare Stream Header
    // and Stream Footer while keeping it useful also for comparing
    // two Stream Footers.
    options->backward_size = LZMA_VLI_UNKNOWN;
 
    return LZMA_OK;
}

References in, LZMA_DATA_ERROR, LZMA_FORMAT_ERROR, lzma_header_magic, LZMA_OK, LZMA_OPTIONS_ERROR, LZMA_STREAM_FLAGS_SIZE, LZMA_VLI_UNKNOWN, options, read32le(), and stream_flags_decode().

stream_flags_decode()

static bool stream_flags_decode ( lzma_stream_flags *  options, const uint8_t *  in  )

static

Definition at line 17 of file stream_flags_decoder.c.

{
    // Reserved bits must be unset.
    if (in[0] != 0x00 || (in[1] & 0xF0))
        return true;
 
    options->version = 0;
    options->check = in[1] & 0x0F;
 
    return false;
}

References in, and options.

Referenced by LZMA_API().