diff options
author | Denis Vlasenko <vda.linux@googlemail.com> | 2008-02-19 14:26:28 +0300 |
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committer | Denis Vlasenko <vda.linux@googlemail.com> | 2008-02-19 14:26:28 +0300 |
commit | 431a7c9c53b69a7416091721da673bcff7c91a02 (patch) | |
tree | 03cbe0e15af01d82b05138f0db41d44179262a3f /archival/libunarchive/get_header_tar.c | |
parent | a37e7134f76b7661b86bb9cc926f28f81b1e1109 (diff) |
tar: optional autodetection of gz/bz2 compressed tarballs.
+130 bytes. Closes bug 992.
Diffstat (limited to 'archival/libunarchive/get_header_tar.c')
-rw-r--r-- | archival/libunarchive/get_header_tar.c | 52 |
1 files changed, 44 insertions, 8 deletions
diff --git a/archival/libunarchive/get_header_tar.c b/archival/libunarchive/get_header_tar.c index 893cd5b79..54c8f7665 100644 --- a/archival/libunarchive/get_header_tar.c +++ b/archival/libunarchive/get_header_tar.c @@ -46,6 +46,9 @@ void BUG_tar_header_size(void); char get_header_tar(archive_handle_t *archive_handle) { static smallint end; +#if ENABLE_FEATURE_TAR_AUTODETECT + static smallint not_first; +#endif file_header_t *file_header = archive_handle->file_header; struct { @@ -115,7 +118,7 @@ char get_header_tar(archive_handle_t *archive_handle) * Read until the end to empty the pipe from gz or bz2 */ while (full_read(archive_handle->src_fd, &tar, 512) == 512) - /* repeat */; + continue; return EXIT_FAILURE; } end = 1; @@ -123,16 +126,49 @@ char get_header_tar(archive_handle_t *archive_handle) } end = 0; - /* Check header has valid magic, "ustar" is for the proper tar - * 0's are for the old tar format - */ - if (strncmp(tar.magic, "ustar", 5) != 0) { -#if ENABLE_FEATURE_TAR_OLDGNU_COMPATIBILITY - if (memcmp(tar.magic, "\0\0\0\0", 5) != 0) + /* Check header has valid magic, "ustar" is for the proper tar, + * five NULs are for the old tar format */ + if (strncmp(tar.magic, "ustar", 5) != 0 + && (!ENABLE_FEATURE_TAR_OLDGNU_COMPATIBILITY + || memcmp(tar.magic, "\0\0\0\0", 5) != 0) + ) { +#if ENABLE_FEATURE_TAR_AUTODETECT + char (*get_header_ptr)(archive_handle_t *); + + /* tar gz/bz autodetect: check for gz/bz2 magic. + * If it is the very first block, and we see the magic, + * we can switch to get_header_tar_gz/bz2/lzma(). + * Needs seekable fd. I wish recv(MSG_PEEK) would work + * on any fd... */ + if (not_first) + goto err; +#if ENABLE_FEATURE_TAR_GZIP + if (tar.name[0] == 0x1f && tar.name[1] == 0x8b) { /* gzip */ + get_header_ptr = get_header_tar_gz; + } else #endif - bb_error_msg_and_die("invalid tar magic"); +#if ENABLE_FEATURE_TAR_BZIP2 + if (tar.name[0] == 'B' && tar.name[1] == 'Z' + && tar.name[2] == 'h' && isdigit(tar.name[3]) + ) { /* bzip2 */ + get_header_ptr = get_header_tar_bz2; + } else +#endif + goto err; + if (lseek(archive_handle->src_fd, -512, SEEK_CUR) != 0) + goto err; + while (get_header_ptr(archive_handle) == EXIT_SUCCESS) + continue; + return EXIT_FAILURE; + err: +#endif /* FEATURE_TAR_AUTODETECT */ + bb_error_msg_and_die("invalid tar magic"); } +#if ENABLE_FEATURE_TAR_AUTODETECT + not_first = 1; +#endif + /* Do checksum on headers. * POSIX says that checksum is done on unsigned bytes, but * Sun and HP-UX gets it wrong... more details in |