From 8317fe12763fe8715fb81eaa1a81e1b96ac73937 Mon Sep 17 00:00:00 2001
From: dsl <dsl@NetBSD.org>
Date: Sun, 17 Oct 2004 18:49:55 +0000
Subject: [PATCH] Add an option --chroot to tar.  Causes it to chroot(".")
 before doing an extract.  With -h this will cause existing absolute symlinks
 to be treated as relative to the current directory. Helps sysinst handle
 existing symlinks in the target system. Remove 'L' from the usage (got spilt
 into 'h' and 'H' many moons ago) Add 'S' to usage, and put into correct place
 in options list.

---
 bin/pax/ar_subs.c |  8 ++++++--
 bin/pax/extern.h  |  3 ++-
 bin/pax/options.c | 14 ++++++++++----
 bin/pax/tar.1     | 12 ++++++++++--
 4 files changed, 28 insertions(+), 9 deletions(-)

diff --git a/bin/pax/ar_subs.c b/bin/pax/ar_subs.c
index 396471dc9542..09c6beda4714 100644
--- a/bin/pax/ar_subs.c
+++ b/bin/pax/ar_subs.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: ar_subs.c,v 1.32 2004/10/10 22:03:08 christos Exp $	*/
+/*	$NetBSD: ar_subs.c,v 1.33 2004/10/17 18:49:55 dsl Exp $	*/
 
 /*-
  * Copyright (c) 1992 Keith Muller.
@@ -42,7 +42,7 @@
 #if 0
 static char sccsid[] = "@(#)ar_subs.c	8.2 (Berkeley) 4/18/94";
 #else
-__RCSID("$NetBSD: ar_subs.c,v 1.32 2004/10/10 22:03:08 christos Exp $");
+__RCSID("$NetBSD: ar_subs.c,v 1.33 2004/10/17 18:49:55 dsl Exp $");
 #endif
 #endif /* not lint */
 
@@ -198,6 +198,10 @@ extract(void)
 		return;
 
 	now = time((time_t *)NULL);
+	if (do_chroot && fchroot(cwdfd) != 0) {
+		syswarn(1, errno, "Can't fchroot to \".\"");
+		return;
+	}
 
 	/*
 	 * When we are doing interactive rename, we store the mapping of names
diff --git a/bin/pax/extern.h b/bin/pax/extern.h
index b8efa61be2c5..7f858d0b3acd 100644
--- a/bin/pax/extern.h
+++ b/bin/pax/extern.h
@@ -1,4 +1,4 @@
-/*	$NetBSD: extern.h,v 1.45 2004/09/22 15:03:18 christos Exp $	*/
+/*	$NetBSD: extern.h,v 1.46 2004/10/17 18:49:55 dsl Exp $	*/
 
 /*-
  * Copyright (c) 1992 Keith Muller.
@@ -203,6 +203,7 @@ int opt_add(const char *);
 int bad_opt(void);
 int mkpath(char *);
 char *chdname;
+int do_chroot;
 
 /*
  * pat_rep.c
diff --git a/bin/pax/options.c b/bin/pax/options.c
index 781f38780980..b92d0064ff73 100644
--- a/bin/pax/options.c
+++ b/bin/pax/options.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: options.c,v 1.79 2004/10/10 22:05:26 christos Exp $	*/
+/*	$NetBSD: options.c,v 1.80 2004/10/17 18:49:55 dsl Exp $	*/
 
 /*-
  * Copyright (c) 1992 Keith Muller.
@@ -42,7 +42,7 @@
 #if 0
 static char sccsid[] = "@(#)options.c	8.2 (Berkeley) 4/18/94";
 #else
-__RCSID("$NetBSD: options.c,v 1.79 2004/10/10 22:05:26 christos Exp $");
+__RCSID("$NetBSD: options.c,v 1.80 2004/10/17 18:49:55 dsl Exp $");
 #endif
 #endif /* not lint */
 
@@ -123,6 +123,7 @@ static int getline_error;
 #define	OPT_INSECURE			14
 #define	OPT_STRICT			15
 #define	OPT_SPARSE			16
+#define	OPT_CHROOT			17
 
 /*
  *	Format specific routine table - MUST BE IN SORTED ORDER BY NAME
@@ -724,6 +725,7 @@ struct option tar_longopts[] = {
 	{ "directory",		required_argument,	0,	'C' },
 	{ "to-stdout",		no_argument,		0,	'O' },
 	{ "absolute-paths",	no_argument,		0,	'P' },
+	{ "sparse",		no_argument,		0,	'S' },
 	{ "files-from",		required_argument,	0,	'T' },
 	{ "exclude-from",	required_argument,	0,	'X' },
 	{ "compress",		no_argument,		0,	'Z' },
@@ -742,7 +744,8 @@ struct option tar_longopts[] = {
 						OPT_INSECURE },
 	{ "exclude",		required_argument,	0,
 						OPT_EXCLUDE },
-	{ "sparse",		no_argument,		0,	'S' },
+	{ "chroot",		no_argument,		0,
+						OPT_CHROOT },
 #if 0 /* Not implemented */
 	{ "catenate",		no_argument,		0,	'A' },	/* F */
 	{ "concatenate",	no_argument,		0,	'A' },	/* F */
@@ -1064,6 +1067,9 @@ tar_options(int argc, char **argv)
 			if (tar_gnutar_minus_minus_exclude(optarg) != 0)
 				tar_usage();
 			break;
+		case OPT_CHROOT:
+			do_chroot = 1;
+			break;
 		default:
 			tar_usage();
 			break;
@@ -2003,7 +2009,7 @@ pax_usage(void)
 void
 tar_usage(void)
 {
-	(void)fputs("usage: tar [-]{crtux}[-befhjlmopqvwzHLOPXZ014578] [archive] "
+	(void)fputs("usage: tar [-]{crtux}[-befhjlmopqvwzHOPSXZ014578] [archive] "
 		    "[blocksize]\n"
 		    "           [-C directory] [-T file] [-s replstr] "
 		    "[file ...]\n", stderr);
diff --git a/bin/pax/tar.1 b/bin/pax/tar.1
index b8e81d7d3a8f..1ed236561cfd 100644
--- a/bin/pax/tar.1
+++ b/bin/pax/tar.1
@@ -1,4 +1,4 @@
-.\" $NetBSD: tar.1,v 1.17 2004/09/27 07:41:54 wiz Exp $
+.\" $NetBSD: tar.1,v 1.18 2004/10/17 18:49:55 dsl Exp $
 .\"
 .\" Copyright (c) 1996 SigmaSoft, Th. Lockert
 .\" All rights reserved.
@@ -34,7 +34,7 @@
 .Sh SYNOPSIS
 .Nm tar
 .Sm off
-.Oo \&- Oc {crtux} Op Fl befhjklmopqvwzHLOPSXZ014578
+.Oo \&- Oc {crtux} Op Fl befhjklmopqvwzHOPSXZ014578
 .Sm on
 .Op Ar archive
 .Op Ar blocksize
@@ -235,6 +235,14 @@ Compress archive using compress.
 Do not enable GNU tar extensions such as long filenames and long link names.
 .It Fl -atime-preserve
 Preserve file access times.
+.It Fl -chroot
+.Fn chroot
+to the current directory before extracting files.
+Use with
+.Fl x
+and
+.Fl h
+to make absolute symlinks be relative to the current directory.
 .It Fl -unlink
 Ignored, only accepted for compatibility with other
 .Nm