1 /* SPDX-License-Identifier: 0BSD */ 2 3 /* 4 * Definitions for handling the .xz file format 5 * 6 * Author: Lasse Collin <lasse.collin@tukaani.org> 7 */ 8 9 #ifndef XZ_STREAM_H 10 #define XZ_STREAM_H 11 12 #if defined(__KERNEL__) && !XZ_INTERNAL_CRC32 13 # include <linux/crc32.h> 14 # undef crc32 15 # define xz_crc32(buf, size, crc) \ 16 (~crc32_le(~(uint32_t)(crc), buf, size)) 17 #endif 18 19 /* 20 * See the .xz file format specification at 21 * https://tukaani.org/xz/xz-file-format.txt 22 * to understand the container format. 23 */ 24 25 #define STREAM_HEADER_SIZE 12 26 27 #define HEADER_MAGIC "\3757zXZ" 28 #define HEADER_MAGIC_SIZE 6 29 30 #define FOOTER_MAGIC "YZ" 31 #define FOOTER_MAGIC_SIZE 2 32 33 /* 34 * Variable-length integer can hold a 63-bit unsigned integer or a special 35 * value indicating that the value is unknown. 36 * 37 * Experimental: vli_type can be defined to uint32_t to save a few bytes 38 * in code size (no effect on speed). Doing so limits the uncompressed and 39 * compressed size of the file to less than 256 MiB and may also weaken 40 * error detection slightly. 41 */ 42 typedef uint64_t vli_type; 43 44 #define VLI_MAX ((vli_type)-1 / 2) 45 #define VLI_UNKNOWN ((vli_type)-1) 46 47 /* Maximum encoded size of a VLI */ 48 #define VLI_BYTES_MAX (sizeof(vli_type) * 8 / 7) 49 50 /* Integrity Check types */ 51 enum xz_check { 52 XZ_CHECK_NONE = 0, 53 XZ_CHECK_CRC32 = 1, 54 XZ_CHECK_CRC64 = 4, 55 XZ_CHECK_SHA256 = 10 56 }; 57 58 /* Maximum possible Check ID */ 59 #define XZ_CHECK_MAX 15 60 61 #endif 62