| /* vi: set sw=4 ts=4: */ |
| /* Licensed under GPLv2 or later, see file LICENSE in this tarball for details. |
| * |
| * FIXME: |
| * In privileged mode if uname and gname map to a uid and gid then use the |
| * mapped value instead of the uid/gid values in tar header |
| * |
| * References: |
| * GNU tar and star man pages, |
| * Opengroup's ustar interchange format, |
| * http://www.opengroup.org/onlinepubs/007904975/utilities/pax.html |
| */ |
| |
| #include "libbb.h" |
| #include "unarchive.h" |
| |
| #ifdef CONFIG_FEATURE_TAR_GNU_EXTENSIONS |
| static char *longname = NULL; |
| static char *linkname = NULL; |
| #endif |
| |
| char get_header_tar(archive_handle_t *archive_handle) |
| { |
| file_header_t *file_header = archive_handle->file_header; |
| union { |
| /* ustar header, Posix 1003.1 */ |
| unsigned char raw[512]; |
| struct { |
| char name[100]; /* 0-99 */ |
| char mode[8]; /* 100-107 */ |
| char uid[8]; /* 108-115 */ |
| char gid[8]; /* 116-123 */ |
| char size[12]; /* 124-135 */ |
| char mtime[12]; /* 136-147 */ |
| char chksum[8]; /* 148-155 */ |
| char typeflag; /* 156-156 */ |
| char linkname[100]; /* 157-256 */ |
| char magic[6]; /* 257-262 */ |
| char version[2]; /* 263-264 */ |
| char uname[32]; /* 265-296 */ |
| char gname[32]; /* 297-328 */ |
| char devmajor[8]; /* 329-336 */ |
| char devminor[8]; /* 337-344 */ |
| char prefix[155]; /* 345-499 */ |
| char padding[12]; /* 500-512 */ |
| } formatted; |
| } tar; |
| long sum = 0; |
| long i; |
| static int end = 0; |
| |
| /* Align header */ |
| data_align(archive_handle, 512); |
| |
| xread(archive_handle->src_fd, tar.raw, 512); |
| archive_handle->offset += 512; |
| |
| /* If there is no filename its an empty header */ |
| if (tar.formatted.name[0] == 0) { |
| if (end) { |
| /* This is the second consecutive empty header! End of archive! |
| * Read until the end to empty the pipe from gz or bz2 |
| */ |
| while (full_read(archive_handle->src_fd, tar.raw, 512) == 512); |
| return EXIT_FAILURE; |
| } |
| end = 1; |
| return EXIT_SUCCESS; |
| } |
| end = 0; |
| |
| /* Check header has valid magic, "ustar" is for the proper tar |
| * 0's are for the old tar format |
| */ |
| if (strncmp(tar.formatted.magic, "ustar", 5) != 0) { |
| #ifdef CONFIG_FEATURE_TAR_OLDGNU_COMPATIBILITY |
| if (strncmp(tar.formatted.magic, "\0\0\0\0\0", 5) != 0) |
| #endif |
| bb_error_msg_and_die("invalid tar magic"); |
| } |
| /* Do checksum on headers */ |
| for (i = 0; i < 148 ; i++) { |
| sum += tar.raw[i]; |
| } |
| sum += ' ' * 8; |
| for (i = 156; i < 512 ; i++) { |
| sum += tar.raw[i]; |
| } |
| if (sum != xstrtoul(tar.formatted.chksum, 8)) { |
| bb_error_msg_and_die("invalid tar header checksum"); |
| } |
| |
| #ifdef CONFIG_FEATURE_TAR_GNU_EXTENSIONS |
| if (longname) { |
| file_header->name = longname; |
| longname = NULL; |
| } |
| else if (linkname) { |
| file_header->name = linkname; |
| linkname = NULL; |
| } else |
| #endif |
| { |
| file_header->name = xstrndup(tar.formatted.name, 100); |
| if (tar.formatted.prefix[0]) { |
| char *temp = file_header->name; |
| file_header->name = concat_path_file(tar.formatted.prefix, temp); |
| free(temp); |
| } |
| } |
| |
| file_header->uid = xstrtoul(tar.formatted.uid, 8); |
| file_header->gid = xstrtoul(tar.formatted.gid, 8); |
| // TODO: LFS support |
| file_header->size = xstrtoul(tar.formatted.size, 8); |
| file_header->mtime = xstrtoul(tar.formatted.mtime, 8); |
| file_header->link_name = tar.formatted.linkname[0] ? |
| xstrdup(tar.formatted.linkname) : NULL; |
| file_header->device = makedev(xstrtoul(tar.formatted.devmajor, 8), |
| xstrtoul(tar.formatted.devminor, 8)); |
| |
| /* Set bits 0-11 of the files mode */ |
| file_header->mode = 07777 & xstrtoul(tar.formatted.mode, 8); |
| |
| /* Set bits 12-15 of the files mode */ |
| switch (tar.formatted.typeflag) { |
| /* busybox identifies hard links as being regular files with 0 size and a link name */ |
| case '1': |
| file_header->mode |= S_IFREG; |
| break; |
| case '7': |
| /* Reserved for high performance files, treat as normal file */ |
| case 0: |
| case '0': |
| #ifdef CONFIG_FEATURE_TAR_OLDGNU_COMPATIBILITY |
| if (last_char_is(file_header->name, '/')) { |
| file_header->mode |= S_IFDIR; |
| } else |
| #endif |
| file_header->mode |= S_IFREG; |
| break; |
| case '2': |
| file_header->mode |= S_IFLNK; |
| break; |
| case '3': |
| file_header->mode |= S_IFCHR; |
| break; |
| case '4': |
| file_header->mode |= S_IFBLK; |
| break; |
| case '5': |
| file_header->mode |= S_IFDIR; |
| break; |
| case '6': |
| file_header->mode |= S_IFIFO; |
| break; |
| #ifdef CONFIG_FEATURE_TAR_GNU_EXTENSIONS |
| case 'L': { |
| longname = xzalloc(file_header->size + 1); |
| xread(archive_handle->src_fd, longname, file_header->size); |
| archive_handle->offset += file_header->size; |
| |
| return get_header_tar(archive_handle); |
| } |
| case 'K': { |
| linkname = xzalloc(file_header->size + 1); |
| xread(archive_handle->src_fd, linkname, file_header->size); |
| archive_handle->offset += file_header->size; |
| |
| file_header->name = linkname; |
| return get_header_tar(archive_handle); |
| } |
| case 'D': /* GNU dump dir */ |
| case 'M': /* Continuation of multi volume archive*/ |
| case 'N': /* Old GNU for names > 100 characters */ |
| case 'S': /* Sparse file */ |
| case 'V': /* Volume header */ |
| #endif |
| case 'g': /* pax global header */ |
| case 'x': /* pax extended header */ |
| bb_error_msg("ignoring extension type %c", tar.formatted.typeflag); |
| break; |
| default: |
| bb_error_msg("unknown typeflag: 0x%x", tar.formatted.typeflag); |
| } |
| { /* Strip trailing '/' in directories */ |
| /* Must be done after mode is set as '/' is used to check if its a directory */ |
| char *tmp = last_char_is(file_header->name, '/'); |
| if (tmp) { |
| *tmp = '\0'; |
| } |
| } |
| |
| if (archive_handle->filter(archive_handle) == EXIT_SUCCESS) { |
| archive_handle->action_header(archive_handle->file_header); |
| archive_handle->flags |= ARCHIVE_EXTRACT_QUIET; |
| archive_handle->action_data(archive_handle); |
| llist_add_to(&(archive_handle->passed), file_header->name); |
| } else { |
| data_skip(archive_handle); |
| } |
| archive_handle->offset += file_header->size; |
| |
| free(file_header->link_name); |
| |
| return EXIT_SUCCESS; |
| } |