Backport unit test of recent libnbd API addition

2023-11-17 03:05:27 +00:00
4 changed files with 250 additions and 2 deletions
--- a/.libnbd.metadata
+++ b/.libnbd.metadata
@ -0,0 +1,2 @@
+4f99e6f21edffe62b394aa9c7fb68149e6d4d5e4 libnbd-1.18.1.tar.gz
+f9a431cb1f235dabb4482f961da8d19a9e3719c8 libnbd-1.18.1.tar.gz.sig
--- a/0002-docs-Fix-incorrect-xref-in-libnbd-release-notes-for-.patch
+++ b/0002-docs-Fix-incorrect-xref-in-libnbd-release-notes-for-.patch
@ -0,0 +1,34 @@
+From c39e31b7a20c7dc8aa12c5fa3f1742824e1e0c76 Mon Sep 17 00:00:00 2001
+From: "Richard W.M. Jones" <rjones@redhat.com>
+Date: Thu, 9 Nov 2023 09:40:30 +0000
+Subject: [libnbd PATCH] docs: Fix incorrect xref in libnbd-release-notes for
+ 1.18
+Content-type: text/plain
+
+LIBNBD_STRICT_AUTO_FLAG was added to nbd_set_strict_mode(3).
+
+Reported-by: Vera Wu
+(cherry picked from commit 4fef3dbc07e631fce58487d25d991e83bbb424b1)
+Signed-off-by: Eric Blake <eblake@redhat.com>
+---
+ docs/libnbd-release-notes-1.18.pod | 4 ++--
+ 1 file changed, 2 insertions(+), 2 deletions(-)
+
+diff --git a/docs/libnbd-release-notes-1.18.pod b/docs/libnbd-release-notes-1.18.pod
+index 935fab11..836ebe19 100644
+--- a/docs/libnbd-release-notes-1.18.pod
+++ b/docs/libnbd-release-notes-1.18.pod
+@@ -84,8 +84,8 @@ Golang, OCaml and Python language bindings (Eric Blake).
+
+ L<nbd_shutdown(3)> now works correctly when in opt mode (Eric Blake).
+
+-L<nbd_set_string(3)> adds C<LIBNBD_STRICT_AUTO_FLAG> which allows the
+-client to test how servers behave when the payload length flag is
+L<nbd_set_strict_mode(3)> adds C<LIBNBD_STRICT_AUTO_FLAG> which allows
+the client to test how servers behave when the payload length flag is
+ adjusted (Eric Blake).
+
+ =head2 Protocol
+-- 
+2.41.0
+
--- a/0003-tests-Check-behavior-of-nbd_set_strict_mode-STRICT_A.patch
+++ b/0003-tests-Check-behavior-of-nbd_set_strict_mode-STRICT_A.patch
@ -0,0 +1,206 @@
+From 32cb9ab9f1701b1a1a826b48f2083cb75adf1e87 Mon Sep 17 00:00:00 2001
+From: Eric Blake <eblake@redhat.com>
+Date: Thu, 9 Nov 2023 20:11:08 -0600
+Subject: [libnbd PATCH] tests: Check behavior of
+ nbd_set_strict_mode(STRICT_AUTO_FLAG)
+Content-type: text/plain
+
+While developing extended header support for qemu 8.2, I needed a way
+to make libnbd quickly behave as a non-compliant client to test corner
+cases in qemu's server code; so I wrote commit 5c1dae9236 ("api: Add
+LIBNBD_STRICT_AUTO_FLAG to nbd_set_strict", v1.18.0) to meet my needs.
+However, I failed to codify my manual tests of that bit into a unit
+test for libnbd, until now.  Most sane clients will never call
+nbd_set_strict_mode() in the first place (after all, it is explicitly
+documented as an integration tool, which is how I used it with my qemu
+code development), but it never hurts to make sure we don't break it
+even for the relatively small set of users that would ever use it.
+
+The test added here runs in two parts; if you get a SKIP despite
+having qemu-nbd, then the first part ran successfully before the
+second half gave up due to lack of extended headers in qemu
+(presumably qemu 8.1 or older); if you get a PASS, then both parts
+were run.  However, both parts are inherently fragile, depending on
+behavior known to be in qemu 8.2 - while it is unlikely to change in
+future qemu releases (at least as long as I continue to maintain NBD
+code there), the fact that we are intentionally violating the NBD
+protocol means a different server is within its rights to behave
+differently than qemu 8.2 did.  Hence this test lives in interop/
+rather than tests/ because of its strong ties to a particular qemu.
+
+Signed-off-by: Eric Blake <eblake@redhat.com>
+(cherry picked from commit 54d4426394c372413f55f648d4ad1d21b3395e07)
+Signed-off-by: Eric Blake <eblake@redhat.com>
+---
+ interop/Makefile.am              |   2 +
+ interop/strict-mode-auto-flag.sh | 138 +++++++++++++++++++++++++++++++
+ 2 files changed, 140 insertions(+)
+ create mode 100755 interop/strict-mode-auto-flag.sh
+
+diff --git a/interop/Makefile.am b/interop/Makefile.am
+index d6485adf..ac12d84a 100644
+--- a/interop/Makefile.am
+++ b/interop/Makefile.am
+@@ -28,6 +28,7 @@ EXTRA_DIST = \
+ 	structured-read.sh \
+ 	opt-extended-headers.sh \
+ 	block-status-payload.sh \
+	strict-mode-auto-flag.sh \
+ 	$(NULL)
+
+ TESTS_ENVIRONMENT = \
+@@ -153,6 +154,7 @@ TESTS += \
+ 	interop-qemu-block-size.sh \
+ 	opt-extended-headers.sh \
+ 	block-status-payload.sh \
+	strict-mode-auto-flag.sh \
+ 	$(NULL)
+
+ interop_qemu_nbd_SOURCES = \
+diff --git a/interop/strict-mode-auto-flag.sh b/interop/strict-mode-auto-flag.sh
+new file mode 100755
+index 00000000..8f73ea73
+--- /dev/null
+++ b/interop/strict-mode-auto-flag.sh
+@@ -0,0 +1,138 @@
+#!/usr/bin/env bash
+# nbd client library in userspace
+# Copyright Red Hat
+#
+# This library is free software; you can redistribute it and/or
+# modify it under the terms of the GNU Lesser General Public
+# License as published by the Free Software Foundation; either
+# version 2 of the License, or (at your option) any later version.
+#
+# This library 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
+# Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public
+# License along with this library; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+
+# Test effect of AUTO_FLAG bit in set_strict_mode()
+
+source ../tests/functions.sh
+set -e
+set -x
+
+requires truncate --version
+requires qemu-nbd --version
+requires nbdsh --version
+
+file="strict-mode-auto-flag.file"
+rm -f $file
+cleanup_fn rm -f $file
+
+truncate -s 1M $file
+
+# Unconditional part of test: behavior when extended headers are not in use
+$VG nbdsh -c '
+import errno
+
+h.set_request_extended_headers(False)
+args = ["qemu-nbd", "-f", "raw", "'"$file"'"]
+h.connect_systemd_socket_activation(args)
+assert h.get_extended_headers_negotiated() is False
+
+# STRICT_AUTO_FLAG and STRICT_COMMANDS are on by default
+flags = h.get_strict_mode()
+assert flags & nbd.STRICT_AUTO_FLAG
+assert flags & nbd.STRICT_COMMANDS
+
+# Under STRICT_AUTO_FLAG, using or omitting flag does not matter; client
+# side auto-corrects the flag before passing to server
+h.pwrite(b"1"*512, 0, 0)
+h.pwrite(b"2"*512, 0, nbd.CMD_FLAG_PAYLOAD_LEN)
+
+# Without STRICT_AUTO_FLAG but still STRICT_COMMANDS, client side now sees
+# attempts to use the flag as invalid
+flags = flags & ~nbd.STRICT_AUTO_FLAG
+h.set_strict_mode(flags)
+h.pwrite(b"3"*512, 0, 0)
+stats = h.stats_bytes_sent()
+try:
+  h.pwrite(b"4"*512, 0, nbd.CMD_FLAG_PAYLOAD_LEN)
+  assert False
+except nbd.Error as e:
+  assert e.errnum == errno.EINVAL
+assert stats == h.stats_bytes_sent()
+
+# Warning: fragile test ahead.  Without STRICT_COMMANDS, we send unexpected
+# flag to qemu, and expect failure. For qemu <= 8.1, this is safe (those
+# versions did not know the flag, and correctly reject unknown flags with
+# NBD_EINVAL). For qemu 8.2, this also works (qemu knows the flag, but warns
+# that we were not supposed to send it without extended headers). But if
+# future qemu versions change to start silently ignoring the flag (after all,
+# a write command obviously has a payload even without extended headers, so
+# the flag is redundant for NBD_CMD_WRITE), then we may need to tweak this.
+flags = flags & ~nbd.STRICT_COMMANDS
+h.set_strict_mode(flags)
+h.pwrite(b"5"*512, 0, 0)
+stats = h.stats_bytes_sent()
+try:
+  h.pwrite(b"6"*512, 0, nbd.CMD_FLAG_PAYLOAD_LEN)
+  print("Did newer qemu change behavior?")
+  assert False
+except nbd.Error as e:
+  assert e.errnum == errno.EINVAL
+assert stats < h.stats_bytes_sent()
+
+h.shutdown()
+'
+
+# Conditional part of test: only run if qemu supports extended headers
+requires nbdinfo --has extended-headers -- [ qemu-nbd -r -f raw "$file" ]
+$VG nbdsh -c '
+import errno
+
+args = ["qemu-nbd", "-f", "raw", "'"$file"'"]
+h.connect_systemd_socket_activation(args)
+assert h.get_extended_headers_negotiated() is True
+
+# STRICT_AUTO_FLAG and STRICT_COMMANDS are on by default
+flags = h.get_strict_mode()
+assert flags & nbd.STRICT_AUTO_FLAG
+assert flags & nbd.STRICT_COMMANDS
+
+# Under STRICT_AUTO_FLAG, using or omitting flag does not matter; client
+# side auto-corrects the flag before passing to server
+h.pwrite(b"1"*512, 0, 0)
+h.pwrite(b"2"*512, 0, nbd.CMD_FLAG_PAYLOAD_LEN)
+
+# Without STRICT_AUTO_FLAG but still STRICT_COMMANDS, client side now sees
+# attempts to omit the flag as invalid
+flags = flags & ~nbd.STRICT_AUTO_FLAG
+h.set_strict_mode(flags)
+h.pwrite(b"3"*512, 0, nbd.CMD_FLAG_PAYLOAD_LEN)
+stats = h.stats_bytes_sent()
+try:
+  h.pwrite(b"4"*512, 0, 0)
+  assert False
+except nbd.Error as e:
+  assert e.errnum == errno.EINVAL
+assert stats == h.stats_bytes_sent()
+
+# Warning: fragile test ahead.  Without STRICT_COMMANDS, omitting the flag
+# is a protocol violation. qemu 8.2 silently ignores the violation; but a
+# future qemu might start failing the command, at which point we would need
+# to tweak this part of the test.
+flags = flags & ~nbd.STRICT_COMMANDS
+h.set_strict_mode(flags)
+h.pwrite(b"5"*512, 0, nbd.CMD_FLAG_PAYLOAD_LEN)
+stats = h.stats_bytes_sent()
+try:
+  h.pwrite(b"6"*512, 0, 0)
+except nbd.Error:
+  print("Did newer qemu change behavior?")
+  assert False
+assert stats < h.stats_bytes_sent()
+
+h.shutdown()
+'
+-- 
+2.41.0
+
--- a/libnbd.spec
+++ b/libnbd.spec
@ -2,14 +2,14 @@
 %global verify_tarball_signature 1

 # If there are patches which touch autotools files, set this to 1.
-%global patches_touch_autotools %{nil}
+%global patches_touch_autotools 1

 # The source directory.
 %global source_directory 1.18-stable

 Name:           libnbd
 Version:        1.18.1
-Release:        2%{?dist}
+Release:        3%{?dist}
 Summary:        NBD client library in userspace

 License:        LGPL-2.0-or-later AND BSD-3-Clause
@ -30,6 +30,8 @@ Source3:        copy-patches.sh

 # Patches.
 Patch0001:     0001-generator-Fix-assertion-in-ext-mode-BLOCK_STATUS-CVE.patch
+Patch0002:     0002-docs-Fix-incorrect-xref-in-libnbd-release-notes-for-.patch
+Patch0003:     0003-tests-Check-behavior-of-nbd_set_strict_mode-STRICT_A.patch

 %if 0%{patches_touch_autotools}
 BuildRequires: autoconf, automake, libtool
@ -381,6 +383,10 @@ make %{?_smp_mflags} check || {


 %changelog
+* Mon Nov 13 2023 Eric Blake <eblake@redhat.com> - 1.18.1-3
+- Backport unit test of recent libnbd API addition
+  resolves: RHEL-16292
+
 * Wed Nov 01 2023 Richard W.M. Jones <rjones@redhat.com> - 1.18.1-2
 - Fix assertion in ext-mode BLOCK_STATUS (CVE-2023-5871)
  resolves: RHEL-15143