From 95ebf618b78814ef250bf40737816784cdaef74d Mon Sep 17 00:00:00 2001
From: Glenn L McGrath <bug1@ihug.co.nz>
Date: Thu, 25 Oct 2001 14:18:08 +0000
Subject: *** empty log message ***

---
 archival/libunarchive/get_header_tar.c | 99 ++++++++++++++++++++++++++++++++++
 1 file changed, 99 insertions(+)
 create mode 100644 archival/libunarchive/get_header_tar.c

(limited to 'archival/libunarchive/get_header_tar.c')

diff --git a/archival/libunarchive/get_header_tar.c b/archival/libunarchive/get_header_tar.c
new file mode 100644
index 000000000..639e2dc36
--- /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
-- 
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