diff options
Diffstat (limited to 'busybox/archival/libunarchive/get_header_tar.c')
| -rw-r--r-- | busybox/archival/libunarchive/get_header_tar.c | 215 |
1 files changed, 215 insertions, 0 deletions
diff --git a/busybox/archival/libunarchive/get_header_tar.c b/busybox/archival/libunarchive/get_header_tar.c new file mode 100644 index 0000000..1ad9ac5 --- /dev/null +++ b/busybox/archival/libunarchive/get_header_tar.c @@ -0,0 +1,215 @@ +/* + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU Library General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. + * + * 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 <stdio.h> +#include <stdlib.h> +#include <string.h> +#include "unarchive.h" +#include "libbb.h" + +#ifdef CONFIG_FEATURE_TAR_GNU_EXTENSIONS +static char *longname = NULL; +static char *linkname = NULL; +#endif + +extern 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 */ + } formated; + } tar; + long sum = 0; + long i; + + /* Align header */ + data_align(archive_handle, 512); + + if (bb_full_read(archive_handle->src_fd, tar.raw, 512) != 512) { + /* Assume end of file */ + return(EXIT_FAILURE); + } + archive_handle->offset += 512; + + /* If there is no filename its an empty header */ + if (tar.formated.name[0] == 0) { + return(EXIT_SUCCESS); + } + + /* Check header has valid magic, "ustar" is for the proper tar + * 0's are for the old tar format + */ + if (strncmp(tar.formated.magic, "ustar", 5) != 0) { +#ifdef CONFIG_FEATURE_TAR_OLDGNU_COMPATABILITY + if (strncmp(tar.formated.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 != strtol(tar.formated.chksum, NULL, 8)) { + bb_error_msg("Invalid tar header checksum"); + return(EXIT_FAILURE); + } + +#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 + if (tar.formated.prefix[0] == 0) { + file_header->name = strdup(tar.formated.name); + } else { + file_header->name = concat_path_file(tar.formated.prefix, tar.formated.name); + } + + file_header->uid = strtol(tar.formated.uid, NULL, 8); + file_header->gid = strtol(tar.formated.gid, NULL, 8); + file_header->size = strtol(tar.formated.size, NULL, 8); + file_header->mtime = strtol(tar.formated.mtime, NULL, 8); + file_header->link_name = (tar.formated.linkname[0] != '\0') ? + bb_xstrdup(tar.formated.linkname) : NULL; + file_header->device = makedev(strtol(tar.formated.devmajor, NULL, 8), + strtol(tar.formated.devminor, NULL, 8)); + + /* Set bits 0-11 of the files mode */ + file_header->mode = 07777 & strtol(tar.formated.mode, NULL, 8); + + /* Set bits 12-15 of the files mode */ + switch (tar.formated.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 'x': + case 'g': + bb_error_msg_and_die("pax is not tar"); + break; + case '7': + /* Reserved for high performance files, treat as normal file */ + case 0: + case '0': +#ifdef CONFIG_FEATURE_TAR_OLDGNU_COMPATABILITY + 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 = xmalloc(file_header->size + 1); + archive_xread_all(archive_handle, longname, file_header->size); + longname[file_header->size] = '\0'; + archive_handle->offset += file_header->size; + + return(get_header_tar(archive_handle)); + } + case 'K': { + linkname = xmalloc(file_header->size + 1); + archive_xread_all(archive_handle, linkname, file_header->size); + linkname[file_header->size] = '\0'; + 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 */ + bb_error_msg("Ignoring GNU extension type %c", tar.formated.typeflag); +#endif + default: + bb_error_msg("Unknown typeflag: 0x%x", tar.formated.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); + archive_handle->passed = 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); +} |