Date: Mon, 3 Nov 2008 19:36:56 +0200 (EET) From: Jaakko Heinonen <jh@saunalahti.fi> To: FreeBSD-gnats-submit@FreeBSD.org Subject: bin/128562: [patch] tar(1) problem with hard links and --strip-components Message-ID: <200811031736.mA3HauFV004208@ws64.jh.dy.fi> Resent-Message-ID: <200811031800.mA3I0CMt021441@freefall.freebsd.org>
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>Number: 128562
>Category: bin
>Synopsis: [patch] tar(1) problem with hard links and --strip-components
>Confidential: no
>Severity: non-critical
>Priority: medium
>Responsible: freebsd-bugs
>State: open
>Quarter:
>Keywords:
>Date-Required:
>Class: sw-bug
>Submitter-Id: current-users
>Arrival-Date: Mon Nov 03 18:00:11 UTC 2008
>Closed-Date:
>Last-Modified:
>Originator: Jaakko Heinonen
>Release: FreeBSD 8.0-CURRENT
>Organization:
>Environment:
>Description:
Archives with hard linked files don't work correctly with --strip-components
option. bsdtar doesn't take care of removing pathname elements from hard link
pathnames and thus tries to create hard links incorrectly when extracting
archives.
There is also a small mistake on the bsdtar(1) manual page. --strip-components
option has effect only in the x mode not in the t mode.
>How-To-Repeat:
$ tar --version
bsdtar 2.5.5 - libarchive 2.5.5
$ mkdir test
$ touch test/a
$ ln test/a test/b
$ tar -cf test.tar test
$ rm -fr test
$ tar -x --strip-components 1 -f test.tar
a: Can't create 'a': No such file or directory
tar: Error exit delayed from previous errors.
See also the attached regression test.
>Fix:
I have attached two patches here. The first one is a regression test for
--strip-components and hard links. Second patch is an attempt to fix the bug.
The fix is not complete because tar(1) still fails if the "base file" is
not extracted because of --strip-components. (The last assertion fails in the
regression test.)
--- bsdtar-test_strip_components.diff begins here ---
Index: test/test_strip_components.c
===================================================================
--- test/test_strip_components.c (revision 0)
+++ test/test_strip_components.c (revision 0)
@@ -0,0 +1,68 @@
+/*-
+ * Copyright (c) 2003-2007 Tim Kientzle
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+#include "test.h"
+__FBSDID("$FreeBSD$");
+
+static int
+touch(const char *fn)
+{
+ int fd = open(fn, O_RDWR | O_CREAT | 0644);
+ failure("Couldn't create file '%s', fd=%d, errno=%d (%s)\n",
+ fn, fd, errno, strerror(errno));
+ if (!assert(fd > 0))
+ return (0); /* Failure. */
+ close(fd);
+ return (1); /* Success */
+}
+
+DEFINE_TEST(test_strip_components)
+{
+ struct stat st;
+
+ assertEqualInt(0, mkdir("d0", 0755));
+ assertEqualInt(0, chdir("d0"));
+ assertEqualInt(0, mkdir("d1", 0755));
+ assertEqualInt(0, mkdir("d1/d2", 0755));
+ assertEqualInt(0, mkdir("d1/d2/d3", 0755));
+ assertEqualInt(1, touch("d1/d2/f1"));
+ assertEqualInt(0, link("d1/d2/f1", "l1"));
+ assertEqualInt(0, link("d1/d2/f1", "d1/l2"));
+ assertEqualInt(0, symlink("d1/d2/f1", "s1"));
+ assertEqualInt(0, symlink("d2/f1", "d1/s2"));
+ assertEqualInt(0, chdir(".."));
+
+ assertEqualInt(0, systemf("%s -cf test.tar d0", testprog));
+
+ assertEqualInt(0, mkdir("target", 0755));
+ assertEqualInt(0, systemf("%s -x -C target --strip-components 2 "
+ "-f test.tar", testprog));
+
+ assertEqualInt(-1, lstat("target/d1", &st));
+ assertEqualInt(0, lstat("target/l2", &st));
+ assertEqualInt(0, stat("target/s2", &st));
+ assertEqualInt(0, lstat("target/d2", &st));
+ assertEqualInt(0, lstat("target/d2/f1", &st));
+ assertEqualInt(2, st.st_nlink);
+}
Index: test/Makefile
===================================================================
--- test/Makefile (revision 183691)
+++ test/Makefile (working copy)
@@ -18,6 +18,7 @@ TESTS= \
test_option_q.c \
test_patterns.c \
test_stdio.c \
+ test_strip_components.c \
test_symlink_dir.c \
test_version.c
--- bsdtar-test_strip_components.diff ends here ---
--- bsdtar-strip-components-hardlink.diff begins here ---
Index: bsdtar.1
===================================================================
--- bsdtar.1 (revision 183691)
+++ bsdtar.1 (working copy)
@@ -346,7 +346,7 @@
over it otherwise.
This works similiar to the conv=sparse option of dd.
.It Fl -strip-components Ar count ( Fl W Cm strip-components Ns = Ns Ar count )
-(x and t mode only)
+(x mode only)
Remove the specified number of leading path elements.
Pathnames with fewer elements will be silently skipped.
Note that the pathname is edited after checking inclusion/exclusion patterns
Index: util.c
===================================================================
--- util.c (revision 183691)
+++ util.c (working copy)
@@ -51,6 +51,7 @@
static void bsdtar_vwarnc(struct bsdtar *, int code,
const char *fmt, va_list ap);
+static const char *strip_components(const char *path, int elements);
/*
* Print a string, taking care with any non-printable characters.
@@ -346,6 +347,31 @@
bsdtar->pending_chdir = NULL;
}
+const char *
+strip_components(const char *path, int elements)
+{
+ const char *p = path;
+
+ while (elements > 0) {
+ switch (*p++) {
+ case '/':
+ elements--;
+ path = p;
+ break;
+ case '\0':
+ /* Path is too short, skip it. */
+ return (NULL);
+ }
+ }
+
+ while (*path == '/')
+ ++path;
+ if (*path == '\0')
+ return (NULL);
+
+ return (path);
+}
+
/*
* Handle --strip-components and any future path-rewriting options.
* Returns non-zero if the pathname should not be extracted.
@@ -402,24 +428,17 @@
#endif
/* Strip leading dir names as per --strip-components option. */
- if ((r = bsdtar->strip_components) > 0) {
- const char *p = name;
+ if (bsdtar->strip_components > 0) {
+ const char *linkname = archive_entry_hardlink(entry);
- while (r > 0) {
- switch (*p++) {
- case '/':
- r--;
- name = p;
- break;
- case '\0':
- /* Path is too short, skip it. */
- return (1);
- }
- }
- while (*name == '/')
- ++name;
- if (*name == '\0')
+ if ((name = strip_components(name, bsdtar->strip_components)) ==
+ NULL)
return (1);
+
+ if (linkname != NULL)
+ archive_entry_copy_hardlink(entry,
+ strip_components(linkname,
+ bsdtar->strip_components));
}
/* Strip redundant leading '/' characters. */
--- bsdtar-strip-components-hardlink.diff ends here ---
>Release-Note:
>Audit-Trail:
>Unformatted:
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