From cd14b457565dfc1669c2e598ddc0b3e4bdd3f429 Mon Sep 17 00:00:00 2001
From: Brian Somers <brian@FreeBSD.org>
Date: Sun, 29 Aug 2010 11:56:56 +0000
Subject: [PATCH] Correct an out-by-one error when earlying out ustar filenames
 that are too long.  Filenames escaping this test are caught later on, so the
 bug doesn't cause any breakage.

Document the correct ustar limitations in pax.  As I have no access
to the IEEE 1003.2 spec, I can only assume that the limitations
imposed are in fact correct.

Add regression tests for the filename limitations imposed by pax.

MFC after:	3 weeks
---
 bin/pax/pax.1                      |  4 +-
 bin/pax/tar.c                      |  2 +-
 tools/regression/bin/pax/Makefile  |  8 +++
 tools/regression/bin/pax/regress.t | 91 ++++++++++++++++++++++++++++++
 4 files changed, 103 insertions(+), 2 deletions(-)
 create mode 100644 tools/regression/bin/pax/Makefile
 create mode 100755 tools/regression/bin/pax/regress.t

diff --git a/bin/pax/pax.1 b/bin/pax/pax.1
index 373ec9baa9de..58fba132babd 100644
--- a/bin/pax/pax.1
+++ b/bin/pax/pax.1
@@ -748,7 +748,9 @@ The extended tar interchange format specified in the
 .St -p1003.2
 standard.
 The default blocksize for this format is 10240 bytes.
-Pathnames stored by this format must be 250 characters or less in length.
+Pathnames stored by this format must be 255 characters or less in length.
+The directory part may be at most 155 characters and each path component
+must be less than 100 characters.
 .El
 .Pp
 The
diff --git a/bin/pax/tar.c b/bin/pax/tar.c
index e274df47cf7a..05e8be57ee55 100644
--- a/bin/pax/tar.c
+++ b/bin/pax/tar.c
@@ -1086,7 +1086,7 @@ name_split(char *name, int len)
 	 */
 	if (len <= TNMSZ)
 		return(name);
-	if (len > (TPFSZ + TNMSZ + 1))
+	if (len > TPFSZ + TNMSZ)
 		return(NULL);
 
 	/*
diff --git a/tools/regression/bin/pax/Makefile b/tools/regression/bin/pax/Makefile
new file mode 100644
index 000000000000..dc1a317928d3
--- /dev/null
+++ b/tools/regression/bin/pax/Makefile
@@ -0,0 +1,8 @@
+# $FreeBSD$
+
+test:
+	prove -vmw regress.t
+
+clean:
+	rm -rf ustar-pathnames-[12]
+	rm -f ustar.ok ustar.fail*
diff --git a/tools/regression/bin/pax/regress.t b/tools/regression/bin/pax/regress.t
new file mode 100755
index 000000000000..7c392cbb765c
--- /dev/null
+++ b/tools/regression/bin/pax/regress.t
@@ -0,0 +1,91 @@
+#! /usr/bin/perl
+#
+# $FreeBSD$
+
+use strict;
+use warnings;
+
+use Test::More tests => 6;
+use File::Path qw(rmtree mkpath);
+use Cwd;
+
+my $n = 0;
+sub create_file {
+    my $fn = shift;
+
+    $n++;
+    (my $dir = $fn) =~ s,/[^/]+$,,;
+    mkpath $dir;
+    open my $fd, ">", $fn or die "$fn: $!";
+    print $fd "file $n\n";
+}
+
+
+ustar_pathnames: { SKIP: {
+    # Prove that pax breaks up ustar pathnames properly
+
+    my $top = getcwd . "/ustar-pathnames-1";
+    skip "Current path is too long", 6 if length $top > 92;
+    rmtree $top;
+    my $subdir = "x" . "x" x (92 - length $top);
+    my $work94 = "$top/$subdir";
+    mkpath $work94;		# $work is 94 characters long
+
+    my $x49 = "x" x 49;
+    my $x50 = "x" x 50;
+    my $x60 = "x" x 60;
+    my $x95 = "x" x 95;
+
+    my @paths = (
+	"$work94/x099",		# 99 chars
+	"$work94/xx100",		# 100 chars
+	"$work94/xxx101",		# 101 chars
+	"$work94/$x49/${x50}x199",	# 199 chars
+	"$work94/$x49/${x50}xx200",	# 200 chars
+	"$work94/$x49/${x50}xxx201",	# 201 chars
+	"$work94/$x60/${x95}254",	# 254 chars
+	"$work94/$x60/${x95}x255",	# 255 chars
+    );
+
+    my @l = map { length } @paths;
+
+    my $n = 0;
+    create_file $_ for @paths;
+    system "pax -wf ustar.ok $work94";
+    ok($? == 0, "Wrote 'ustar.ok' containing files with lengths @l");
+
+    (my $orig = $top) =~ s,1$,2,;
+    rmtree $orig;
+    rename $top, $orig;
+
+    system "pax -rf ustar.ok";
+    ok($? == 0, "Restored 'ustar.ok' containing files with lengths @l");
+
+    system "diff -ru $orig $top";
+    ok($? == 0, "Restored files are identical");
+
+    rmtree $top;
+    rename $orig, $top;
+
+    # 256 chars (with components < 100 chars) should not work
+    push @paths, "$work94/x$x60/${x95}x256";	# 256 chars
+    push @l, length $paths[-1];
+    create_file $paths[-1];
+    system "pax -wf ustar.fail1 $work94";
+    ok($?, "Failed to write 'ustar.fail1' containing files with lengths @l");
+
+    # Components with 100 chars shouldn't work
+    unlink $paths[-1];
+    $paths[-1] = "$work94/${x95}xc100";		# 100 char filename
+    $l[-1] = length $paths[-1];
+    create_file $paths[-1];
+    system "pax -wf ustar.fail2 $work94";
+    ok($?, "Failed to write 'ustar.fail2' with a 100 char filename");
+
+    unlink $paths[-1];
+    $paths[-1] = "$work94/${x95}xc100/x";	# 100 char component
+    $l[-1] = length $paths[-1];
+    create_file $paths[-1];
+    system "pax -wf ustar.fail3 $work94";
+    ok($?, "Failed to write 'ustar.fail3' with a 100 char component");
+}}