diff options
| -rw-r--r-- | archival/libarchive/open_transformer.c | 44 | ||||
| -rw-r--r-- | include/bb_archive.h | 6 | ||||
| -rw-r--r-- | include/libbb.h | 1 | ||||
| -rw-r--r-- | libbb/read_printf.c | 12 |
4 files changed, 41 insertions, 22 deletions
diff --git a/archival/libarchive/open_transformer.c b/archival/libarchive/open_transformer.c index 4a4bf39..97bcc32 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) diff --git a/include/bb_archive.h b/include/bb_archive.h index 561dd0c..9b1db5b 100644 --- a/include/bb_archive.h +++ b/include/bb_archive.h @@ -235,6 +235,12 @@ typedef struct transformer_state_t { off_t bytes_in; /* used in unzip code only: needs to know packed size */ uint32_t crc32; time_t mtime; /* gunzip code may set this on exit */ + + union { /* if we read magic, it's saved here */ + uint8_t b[8]; + uint16_t b16[4]; + uint32_t b32[2]; + } magic; } transformer_state_t; void init_transformer_state(transformer_state_t *xstate) FAST_FUNC; diff --git a/include/libbb.h b/include/libbb.h index 57cfce3..33766e9 100644 --- a/include/libbb.h +++ b/include/libbb.h @@ -881,6 +881,7 @@ extern ssize_t open_read_close(const char *filename, void *buf, size_t maxsz) FA extern char *xmalloc_reads(int fd, size_t *maxsz_p) FAST_FUNC; /* Reads block up to *maxsz_p (default: INT_MAX - 4095) */ extern void *xmalloc_read(int fd, size_t *maxsz_p) FAST_FUNC RETURNS_MALLOC; +extern void *xmalloc_read_with_initial_buf(int fd, size_t *maxsz_p, char *buf, size_t total) FAST_FUNC; /* Returns NULL if file can't be opened (default max size: INT_MAX - 4095) */ extern void *xmalloc_open_read_close(const char *filename, size_t *maxsz_p) FAST_FUNC RETURNS_MALLOC; /* Never returns NULL */ diff --git a/libbb/read_printf.c b/libbb/read_printf.c index b6a17cc..cb582c0 100644 --- a/libbb/read_printf.c +++ b/libbb/read_printf.c @@ -102,10 +102,9 @@ char* FAST_FUNC xmalloc_reads(int fd, size_t *maxsz_p) // Read (potentially big) files in one go. File size is estimated // by stat. Extra '\0' byte is appended. -void* FAST_FUNC xmalloc_read(int fd, size_t *maxsz_p) +void* FAST_FUNC xmalloc_read_with_initial_buf(int fd, size_t *maxsz_p, char *buf, size_t total) { - char *buf; - size_t size, rd_size, total; + size_t size, rd_size; size_t to_read; struct stat st; @@ -118,8 +117,6 @@ void* FAST_FUNC xmalloc_read(int fd, size_t *maxsz_p) /* In order to make such files readable, we add small const */ size = (st.st_size | 0x3ff) + 1; - total = 0; - buf = NULL; while (1) { if (to_read < size) size = to_read; @@ -148,6 +145,11 @@ void* FAST_FUNC xmalloc_read(int fd, size_t *maxsz_p) return buf; } +void* FAST_FUNC xmalloc_read(int fd, size_t *maxsz_p) +{ + return xmalloc_read_with_initial_buf(fd, maxsz_p, NULL, 0); +} + #ifdef USING_LSEEK_TO_GET_SIZE /* Alternatively, file size can be obtained by lseek to the end. * The code is slightly bigger. Retained in case fstat approach |