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authorDenys Vlasenko <vda.linux@googlemail.com>2010-07-01 03:12:28 (GMT)
committer Denys Vlasenko <vda.linux@googlemail.com>2010-07-01 03:12:28 (GMT)
commit45f66167fe96de219aac91d842f3e64d857340f6 (patch)
treec141f2aa8213089258125b370a7427bf14937aaf
parent620e863ba24fe9e0126d1540e89a531264021a77 (diff)
downloadbusybox-45f66167fe96de219aac91d842f3e64d857340f6.tar.gz
busybox-45f66167fe96de219aac91d842f3e64d857340f6.tar.bz2
xz compression detection: avoid the need to seek
function old new delta unpack_unxz 12 67 +55 unpack_xz_stream 2357 2373 +16 xmalloc_read 197 199 +2 setup_unzip_on_fd 118 99 -19 rpm2cpio_main 222 203 -19 ------------------------------------------------------------------------------ (add/remove: 0/0 grow/shrink: 3/2 up/down: 73/-38) Total: 35 bytes Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
-rw-r--r--archival/bbunzip.c9
-rw-r--r--archival/libunarchive/decompress_unxz.c4
-rw-r--r--archival/rpm2cpio.c4
-rw-r--r--include/unarchive.h23
-rw-r--r--libbb/read_printf.c4
5 files changed, 30 insertions, 14 deletions
diff --git a/archival/bbunzip.c b/archival/bbunzip.c
index b243afb..832a7bb 100644
--- a/archival/bbunzip.c
+++ b/archival/bbunzip.c
@@ -373,6 +373,15 @@ int unlzma_main(int argc UNUSED_PARAM, char **argv)
static
IF_DESKTOP(long long) int FAST_FUNC unpack_unxz(unpack_info_t *info UNUSED_PARAM)
{
+ struct {
+ uint32_t v1;
+ uint16_t v2;
+ } magic;
+ xread(STDIN_FILENO, &magic, 6);
+ if (magic.v1 != XZ_MAGIC1a || magic.v2 != XZ_MAGIC2a) {
+ bb_error_msg("invalid magic");
+ return -1;
+ }
return unpack_xz_stream(STDIN_FILENO, STDOUT_FILENO);
}
int unxz_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
diff --git a/archival/libunarchive/decompress_unxz.c b/archival/libunarchive/decompress_unxz.c
index 5d7513a..721acd9 100644
--- a/archival/libunarchive/decompress_unxz.c
+++ b/archival/libunarchive/decompress_unxz.c
@@ -56,9 +56,11 @@ unpack_xz_stream(int src_fd, int dst_fd)
if (!crc32_table)
crc32_table = crc32_filltable(NULL, /*endian:*/ 0);
- membuf = xmalloc(2 * BUFSIZ);
memset(&iobuf, 0, sizeof(iobuf));
+ /* Preload XZ file signature */
+ membuf = (void*) strcpy(xmalloc(2 * BUFSIZ), HEADER_MAGIC);
iobuf.in = membuf;
+ iobuf.in_size = HEADER_MAGIC_SIZE;
iobuf.out = membuf + BUFSIZ;
iobuf.out_size = BUFSIZ;
diff --git a/archival/rpm2cpio.c b/archival/rpm2cpio.c
index 1f67fa8..b23d5af 100644
--- a/archival/rpm2cpio.c
+++ b/archival/rpm2cpio.c
@@ -92,8 +92,8 @@ int rpm2cpio_main(int argc UNUSED_PARAM, char **argv)
xread(rpm_fd, magic.b32, sizeof(magic.b32[0]));
if (magic.b32[0] != XZ_MAGIC2)
goto no_magic;
- /* unpack_xz_stream wants fd at position 0 */
- xlseek(rpm_fd, -6, SEEK_CUR);
+ /* unpack_xz_stream wants fd at position 6, no need to seek */
+ //xlseek(rpm_fd, -6, SEEK_CUR);
unpack = unpack_xz_stream;
} else {
no_magic:
diff --git a/include/unarchive.h b/include/unarchive.h
index b4cf160..3b8e157 100644
--- a/include/unarchive.h
+++ b/include/unarchive.h
@@ -7,16 +7,21 @@ PUSH_AND_SET_FUNCTION_VISIBILITY_TO_HIDDEN
enum {
#if BB_BIG_ENDIAN
COMPRESS_MAGIC = 0x1f9d,
- GZIP_MAGIC = 0x1f8b,
- BZIP2_MAGIC = ('B'<<8) + 'Z',
- XZ_MAGIC1 = (0xfd<<8) + '7',
- XZ_MAGIC2 = ((((('z'<<8) + 'X')<<8) + 'Z')<<8) + 0,
+ GZIP_MAGIC = 0x1f8b,
+ BZIP2_MAGIC = 'B' * 256 + 'Z',
+ XZ_MAGIC1 = 0xfd * 256 + '7',
+ XZ_MAGIC2 = (('z' * 256 + 'X') * 256 + 'Z') * 256 + 0,
+ /* Different form: 32 bits, then 16 bits: */
+ XZ_MAGIC1a = ((0xfd * 256 + '7') * 256 + 'z') * 256 + 'X',
+ XZ_MAGIC2a = 'Z' * 256 + 0,
#else
COMPRESS_MAGIC = 0x9d1f,
- GZIP_MAGIC = 0x8b1f,
- BZIP2_MAGIC = ('Z'<<8) + 'B',
- XZ_MAGIC1 = ('7'<<8) + 0xfd,
- XZ_MAGIC2 = (((((0<<8) + 'Z')<<8) + 'X')<<8) + 'z',
+ GZIP_MAGIC = 0x8b1f,
+ BZIP2_MAGIC = 'Z' * 256 + 'B',
+ XZ_MAGIC1 = '7' * 256 + 0xfd,
+ XZ_MAGIC2 = ((0 * 256 + 'Z') * 256 + 'X') * 256 + 'z',
+ XZ_MAGIC1a = (('X' * 256 + 'z') * 256 + '7') * 256 + 0xfd,
+ XZ_MAGIC2a = 0 * 256 + 'Z',
#endif
};
@@ -196,7 +201,7 @@ typedef struct inflate_unzip_result {
} inflate_unzip_result;
IF_DESKTOP(long long) int inflate_unzip(inflate_unzip_result *res, off_t compr_size, int src_fd, int dst_fd) FAST_FUNC;
-/* xz unpacker takes .xz stream from offset 0 */
+/* xz unpacker takes .xz stream from offset 6 */
IF_DESKTOP(long long) int unpack_xz_stream(int src_fd, int dst_fd) FAST_FUNC;
/* lzma unpacker takes .lzma stream from offset 0 */
IF_DESKTOP(long long) int unpack_lzma_stream(int src_fd, int dst_fd) FAST_FUNC;
diff --git a/libbb/read_printf.c b/libbb/read_printf.c
index 3aee075..6780b94 100644
--- a/libbb/read_printf.c
+++ b/libbb/read_printf.c
@@ -296,8 +296,8 @@ void FAST_FUNC setup_unzip_on_fd(int fd /*, int fail_if_not_detected*/)
if (magic.b32[0] == XZ_MAGIC2) {
# if BB_MMU
xformer = unpack_xz_stream;
- /* unpack_xz_stream wants fd at position 0 */
- xlseek(fd, offset, SEEK_CUR);
+ /* unpack_xz_stream wants fd at position 6, no need to seek */
+ //xlseek(fd, offset, SEEK_CUR);
# else
xformer_prog = "unxz";
# endif