diff options
Diffstat (limited to 'archival/libarchive')
| -rw-r--r-- | archival/libarchive/open_transformer.c | 44 |
1 files changed, 27 insertions, 17 deletions
diff --git a/archival/libarchive/open_transformer.c b/archival/libarchive/open_transformer.c index 4a4bf3916..97bcc32f0 100644 --- a/archival/libarchive/open_transformer.c +++ b/archival/libarchive/open_transformer.c @@ -159,47 +159,44 @@ void FAST_FUNC fork_transformer(int fd, const char *transform_prog) */ static transformer_state_t *setup_transformer_on_fd(int fd, int fail_if_not_compressed) { - union { - uint8_t b[4]; - uint16_t b16[2]; - uint32_t b32[1]; - } magic; transformer_state_t *xstate; xstate = xzalloc(sizeof(*xstate)); xstate->src_fd = fd; - xstate->signature_skipped = 2; /* .gz and .bz2 both have 2-byte signature, and their * unpack_XXX_stream wants this header skipped. */ - xread(fd, magic.b16, sizeof(magic.b16[0])); + xstate->signature_skipped = 2; + xread(fd, xstate->magic.b16, 2); if (ENABLE_FEATURE_SEAMLESS_GZ - && magic.b16[0] == GZIP_MAGIC + && xstate->magic.b16[0] == GZIP_MAGIC ) { xstate->xformer = unpack_gz_stream; USE_FOR_NOMMU(xstate->xformer_prog = "gunzip";) goto found_magic; } if (ENABLE_FEATURE_SEAMLESS_Z - && magic.b16[0] == COMPRESS_MAGIC + && xstate->magic.b16[0] == COMPRESS_MAGIC ) { xstate->xformer = unpack_Z_stream; USE_FOR_NOMMU(xstate->xformer_prog = "uncompress";) goto found_magic; } if (ENABLE_FEATURE_SEAMLESS_BZ2 - && magic.b16[0] == BZIP2_MAGIC + && xstate->magic.b16[0] == BZIP2_MAGIC ) { xstate->xformer = unpack_bz2_stream; USE_FOR_NOMMU(xstate->xformer_prog = "bunzip2";) goto found_magic; } if (ENABLE_FEATURE_SEAMLESS_XZ - && magic.b16[0] == XZ_MAGIC1 + && xstate->magic.b16[0] == XZ_MAGIC1 ) { + uint32_t v32; xstate->signature_skipped = 6; - xread(fd, magic.b32, sizeof(magic.b32[0])); - if (magic.b32[0] == XZ_MAGIC2) { + xread(fd, &xstate->magic.b16[1], 4); + move_from_unaligned32(v32, &xstate->magic.b16[1]); + if (v32 == XZ_MAGIC2) { xstate->xformer = unpack_xz_stream; USE_FOR_NOMMU(xstate->xformer_prog = "unxz";) goto found_magic; @@ -344,11 +341,24 @@ void* FAST_FUNC xmalloc_open_zipped_read_close(const char *fname, size_t *maxsz_ *maxsz_p = xstate->mem_output_size; } } else { - /* File is not compressed */ -//FIXME: avoid seek - xlseek(xstate->src_fd, - xstate->signature_skipped, SEEK_CUR); + /* File is not compressed. + * We already read first few bytes, account for that. + * Exmaple where it happens: + * "modinfo MODULE.ko" (not compressed) + * open("MODULE.ko", O_RDONLY|O_LARGEFILE) = 4 + * read(4, "\177E", 2) = 2 + * fstat64(4, ...) + * mmap(...) + * read(4, "LF\2\1\1\0\0\0\0"... + * ...and we avoided seeking on the fd! :) + */ xstate->signature_skipped = 0; - image = xmalloc_read(xstate->src_fd, maxsz_p); + image = xmalloc_read_with_initial_buf( + xstate->src_fd, + maxsz_p, + xmemdup(&xstate->magic, xstate->signature_skipped), + xstate->signature_skipped + ); } if (!image) |