diff options
Diffstat (limited to 'archival/libunarchive')
| -rw-r--r-- | archival/libunarchive/get_header_tar.c | 53 |
1 files changed, 34 insertions, 19 deletions
diff --git a/archival/libunarchive/get_header_tar.c b/archival/libunarchive/get_header_tar.c index b785d63..583f6f8 100644 --- a/archival/libunarchive/get_header_tar.c +++ b/archival/libunarchive/get_header_tar.c @@ -40,11 +40,12 @@ static unsigned long long getOctal(char *str, int len) bb_error_msg_and_die("corrupted octal value in tar header"); return v; } +#define GET_OCTAL(a) getOctal((a), sizeof(a)) void BUG_tar_header_size(void); char get_header_tar(archive_handle_t *archive_handle) { - static int end = 0; + static int end; file_header_t *file_header = archive_handle->file_header; struct { @@ -69,18 +70,17 @@ char get_header_tar(archive_handle_t *archive_handle) } tar; char *cp; int sum, i; -#if ENABLE_FEATURE_TAR_GNU_EXTENSIONS int parse_names; -#else - enum { parse_names = 1 }; -#endif if (sizeof(tar) != 512) BUG_tar_header_size(); + again: /* Align header */ data_align(archive_handle, 512); + again_after_align: + xread(archive_handle->src_fd, &tar, 512); archive_handle->offset += 512; @@ -121,13 +121,12 @@ char get_header_tar(archive_handle_t *archive_handle) bb_error_msg_and_die("invalid tar header checksum"); } -#if ENABLE_FEATURE_TAR_GNU_EXTENSIONS - parse_names = (tar.typeflag != 'L' && tar.typeflag != 'K'); -#endif + /* 0 is reserved for high perf file, treat as normal file */ + if (!tar.typeflag) tar.typeflag = '0'; + parse_names = (tar.typeflag >= '0' && tar.typeflag <= '7'); /* getOctal trashes subsequent field, therefore we call it * on fields in reverse order */ -#define GET_OCTAL(a) getOctal((a), sizeof(a)) if (tar.devmajor[0]) { unsigned minor = GET_OCTAL(tar.devminor); unsigned major = GET_OCTAL(tar.devmajor); @@ -147,8 +146,8 @@ char get_header_tar(archive_handle_t *archive_handle) file_header->uid = GET_OCTAL(tar.uid); /* Set bits 0-11 of the files mode */ file_header->mode = 07777 & GET_OCTAL(tar.mode); -#undef GET_OCTAL + file_header->name = NULL; if (!longname && parse_names) { /* we trash mode[0] here, it's ok */ tar.name[sizeof(tar.name)] = '\0'; @@ -158,6 +157,7 @@ char get_header_tar(archive_handle_t *archive_handle) file_header->name = concat_path_file(tar.prefix, tar.name); } else file_header->name = xstrdup(tar.name); + /* FIXME: add check for /../ attacks */ } /* Set bits 12-15 of the files mode */ @@ -168,8 +168,7 @@ char get_header_tar(archive_handle_t *archive_handle) file_header->mode |= S_IFREG; break; case '7': - /* Reserved for high performance files, treat as normal file */ - case 0: + /* case 0: */ case '0': #if ENABLE_FEATURE_TAR_OLDGNU_COMPATIBILITY if (last_char_is(file_header->name, '/')) { @@ -195,18 +194,24 @@ char get_header_tar(archive_handle_t *archive_handle) break; #if ENABLE_FEATURE_TAR_GNU_EXTENSIONS case 'L': - /* paranoia: tar with several consecutive longnames */ + /* free: paranoia: tar with several consecutive longnames */ free(longname); + /* For paranoia reasons we allocate extra NUL char */ longname = xzalloc(file_header->size + 1); + /* We read ASCIZ string, including NUL */ xread(archive_handle->src_fd, longname, file_header->size); archive_handle->offset += file_header->size; - return get_header_tar(archive_handle); + /* return get_header_tar(archive_handle); */ + /* gcc 4.1.1 didn't optimize it into jump */ + /* so we will do it ourself, this also saves stack */ + goto again; case 'K': free(linkname); linkname = xzalloc(file_header->size + 1); xread(archive_handle->src_fd, linkname, file_header->size); archive_handle->offset += file_header->size; - return get_header_tar(archive_handle); + /* return get_header_tar(archive_handle); */ + goto again; case 'D': /* GNU dump dir */ case 'M': /* Continuation of multi volume archive */ case 'N': /* Old GNU for names > 100 characters */ @@ -214,11 +219,19 @@ char get_header_tar(archive_handle_t *archive_handle) case 'V': /* Volume header */ #endif case 'g': /* pax global header */ - case 'x': /* pax extended header */ - bb_error_msg("ignoring extension type %c", tar.typeflag); - break; + case 'x': { /* pax extended header */ + off_t sz; + bb_error_msg("warning: skipping header '%c'", tar.typeflag); + sz = (file_header->size + 511) & ~(off_t)511; + archive_handle->offset += sz; + sz >>= 9; /* sz /= 512 but w/o contortions for signed div */ + while (sz--) + xread(archive_handle->src_fd, &tar, 512); + /* return get_header_tar(archive_handle); */ + goto again_after_align; + } default: - bb_error_msg("unknown typeflag: 0x%x", tar.typeflag); + bb_error_msg_and_die("unknown typeflag: 0x%x", tar.typeflag); } #if ENABLE_FEATURE_TAR_GNU_EXTENSIONS @@ -246,10 +259,12 @@ char get_header_tar(archive_handle_t *archive_handle) llist_add_to(&(archive_handle->passed), file_header->name); } else { data_skip(archive_handle); + free(file_header->name); } archive_handle->offset += file_header->size; free(file_header->link_name); + /* Do not free(file_header->name)! */ return EXIT_SUCCESS; } |