diff options
Diffstat (limited to 'libbb/get_tar_headers.c')
| -rw-r--r-- | libbb/get_tar_headers.c | 111 |
1 files changed, 111 insertions, 0 deletions
diff --git a/libbb/get_tar_headers.c b/libbb/get_tar_headers.c new file mode 100644 index 0000000..5ddf4d9 --- /dev/null +++ b/libbb/get_tar_headers.c @@ -0,0 +1,111 @@ +/* + * 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. + */ +#include <stdlib.h> +#include <string.h> +#include <unistd.h> +#include "libbb.h" + +file_headers_t *get_tar_headers(FILE *tar_stream) +{ + typedef struct raw_tar_header { + 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 */ + } raw_tar_header_t; + + raw_tar_header_t raw_tar_header; + unsigned char *temp = (unsigned char *) &raw_tar_header; + file_headers_t *tar_headers_list = (file_headers_t *) calloc(1, sizeof(file_headers_t)); + file_headers_t *tar_entry; + long i; + long next_header_offset = 0; + long current_offset = 0; + + while (fread((char *) &raw_tar_header, 1, 512, tar_stream) == 512) { + long sum = 0; + current_offset += 512; + + /* Check header has valid magic, unfortunately some tar files + * have empty (0'ed) tar entries at the end, which will + * cause this to fail, so fail silently for now + */ + if (strncmp(raw_tar_header.magic, "ustar", 5) != 0) { +// error_msg("invalid magic, [%s]\n", raw_tar_header.magic); + break; + } + + /* Do checksum on headers */ + for (i = 0; i < 148 ; i++) { + sum += temp[i]; + } + sum += ' ' * 8; + for (i = 156; i < 512 ; i++) { + sum += temp[i]; + } + if (sum != strtol(raw_tar_header.chksum, NULL, 8)) { + error_msg("Invalid tar header checksum"); + break; + } + + /* convert to type'ed variables */ + tar_entry = xcalloc(1, sizeof(file_headers_t)); + tar_entry->name = xstrdup(raw_tar_header.name); + + tar_entry->offset = (off_t) current_offset; + parse_mode(raw_tar_header.mode, &tar_entry->mode); + tar_entry->uid = strtol(raw_tar_header.uid, NULL, 8); + tar_entry->gid = strtol(raw_tar_header.gid, NULL, 8); + tar_entry->size = strtol(raw_tar_header.size, NULL, 8); + tar_entry->mtime = strtol(raw_tar_header.mtime, NULL, 8); + tar_entry->link_name = xstrdup(raw_tar_header.linkname); +// tar_entry->devmajor = strtol(rawHeader->devmajor, NULL, 8); +// tar_entry->devminor = strtol(rawHeader->devminor, NULL, 8); + + tar_headers_list = append_archive_list(tar_headers_list, tar_entry); + + /* start of next header is at */ + next_header_offset = current_offset + tar_entry->size; + + if (tar_entry->size % 512 != 0) { + next_header_offset += (512 - tar_entry->size % 512); + } + /* + * Seek to start of next block, cant use fseek as unzip() does support it + */ + while (current_offset < next_header_offset) { + if (fgetc(tar_stream) == EOF) { + break; + } + current_offset++; + } + } + return(tar_headers_list); +} + |