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Diffstat (limited to 'archival/libunarchive/get_header_tar.c')
-rw-r--r--archival/libunarchive/get_header_tar.c99
1 files changed, 99 insertions, 0 deletions
diff --git a/archival/libunarchive/get_header_tar.c b/archival/libunarchive/get_header_tar.c
new file mode 100644
index 0000000..639e2dc
--- /dev/null
+++ b/archival/libunarchive/get_header_tar.c
@@ -0,0 +1,99 @@
+/*
+ * 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 <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include "unarchive.h"
+#include "libbb.h"
+
+file_header_t *get_header_tar(FILE *tar_stream)
+{
+ union {
+ 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;
+ file_header_t *tar_entry = NULL;
+ long sum = 0;
+ long i;
+
+ if (archive_offset % 512 != 0) {
+ seek_sub_file(tar_stream, 512 - (archive_offset % 512));
+ }
+
+ if (fread(tar.raw, 1, 512, tar_stream) != 512) {
+ /* Unfortunatly its common for tar files to have all sorts of
+ * trailing garbage, fail silently */
+// error_msg("Couldnt read header");
+ return(NULL);
+ }
+ archive_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(tar.formated.magic, "ustar", 5) != 0) {
+ return(NULL);
+ }
+
+ /* 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)) {
+ error_msg("Invalid tar header checksum");
+ return(NULL);
+ }
+
+ /* convert to type'ed variables */
+ tar_entry = xcalloc(1, sizeof(file_header_t));
+ tar_entry->name = xstrdup(tar.formated.name);
+
+ parse_mode(tar.formated.mode, &tar_entry->mode);
+ tar_entry->uid = strtol(tar.formated.uid, NULL, 8);
+ tar_entry->gid = strtol(tar.formated.gid, NULL, 8);
+ tar_entry->size = strtol(tar.formated.size, NULL, 8);
+ tar_entry->mtime = strtol(tar.formated.mtime, NULL, 8);
+ tar_entry->link_name = strlen(tar.formated.linkname) ?
+ xstrdup(tar.formated.linkname) : NULL;
+ tar_entry->device = (strtol(tar.formated.devmajor, NULL, 8) << 8) +
+ strtol(tar.formated.devminor, NULL, 8);
+
+ return(tar_entry);
+} \ No newline at end of file