Merge pull request #239201 from nesteroff/fix-timesync
systemd: disable NSCD when DNSSEC validation is disabled in timesyncd
This commit is contained in:
Florian Klink
GitHub
commit
011e924109
5 changed files with 116 additions and 0 deletions
|
|
@ -46,6 +46,13 @@ with lib;
|
|||
wantedBy = [ "sysinit.target" ];
|
||||
aliases = [ "dbus-org.freedesktop.timesync1.service" ];
|
||||
restartTriggers = [ config.environment.etc."systemd/timesyncd.conf".source ];
|
||||
# systemd-timesyncd disables DNSSEC validation in the nss-resolve module by setting SYSTEMD_NSS_RESOLVE_VALIDATE to 0 in the unit file.
|
||||
# This is required in order to solve the chicken-and-egg problem when DNSSEC validation needs the correct time to work, but to set the
|
||||
# correct time, we need to connect to an NTP server, which usually requires resolving its hostname.
|
||||
# In order for nss-resolve to be able to read this environment variable we patch systemd-timesyncd to disable NSCD and use NSS modules directly.
|
||||
# This means that systemd-timesyncd needs to have NSS modules path in LD_LIBRARY_PATH. When systemd-resolved is disabled we still need to set
|
||||
# NSS module path so that systemd-timesyncd keeps using other NSS modules that are configured in the system.
|
||||
environment.LD_LIBRARY_PATH = config.system.nssModules.path;
|
||||
|
||||
preStart = (
|
||||
# Ensure that we have some stored time to prevent
|
||||
|
|
|
|||
|
|
@ -851,6 +851,7 @@ in {
|
|||
systemd-shutdown = handleTest ./systemd-shutdown.nix {};
|
||||
systemd-sysupdate = runTest ./systemd-sysupdate.nix;
|
||||
systemd-timesyncd = handleTest ./systemd-timesyncd.nix {};
|
||||
systemd-timesyncd-nscd-dnssec = handleTest ./systemd-timesyncd-nscd-dnssec.nix {};
|
||||
systemd-user-tmpfiles-rules = handleTest ./systemd-user-tmpfiles-rules.nix {};
|
||||
systemd-misc = handleTest ./systemd-misc.nix {};
|
||||
systemd-userdbd = handleTest ./systemd-userdbd.nix {};
|
||||
|
|
|
|||
61
nixos/tests/systemd-timesyncd-nscd-dnssec.nix
Normal file
61
nixos/tests/systemd-timesyncd-nscd-dnssec.nix
Normal file
|
|
@ -0,0 +1,61 @@
|
|||
# This test verifies that systemd-timesyncd can resolve the NTP server hostname when DNSSEC validation
|
||||
# fails even though it is enforced in the systemd-resolved settings. It is required in order to solve
|
||||
# the chicken-and-egg problem when DNSSEC validation needs the correct time to work, but to set the
|
||||
# correct time, we need to connect to an NTP server, which usually requires resolving its hostname.
|
||||
#
|
||||
# This test does the following:
|
||||
# - Sets up a DNS server (tinydns) listening on the eth1 ip addess, serving .ntp and fake.ntp records.
|
||||
# - Configures that DNS server as a resolver and enables DNSSEC in systemd-resolved settings.
|
||||
# - Configures systemd-timesyncd to use fake.ntp hostname as an NTP server.
|
||||
# - Performs a regular DNS lookup, to ensure it fails due to broken DNSSEC.
|
||||
# - Waits until systemd-timesyncd resolves fake.ntp by checking its debug output.
|
||||
# Here, we don't expect systemd-timesyncd to connect and synchronize time because there is no NTP
|
||||
# server running. For this test to succeed, we only need to ensure that systemd-timesyncd
|
||||
# resolves the IP address of the fake.ntp host.
|
||||
|
||||
import ./make-test-python.nix ({ pkgs, ... }:
|
||||
|
||||
let
|
||||
ntpHostname = "fake.ntp";
|
||||
ntpIP = "192.0.2.1";
|
||||
in
|
||||
{
|
||||
name = "systemd-timesyncd";
|
||||
nodes.machine = { pkgs, lib, config, ... }:
|
||||
let
|
||||
eth1IP = (lib.head config.networking.interfaces.eth1.ipv4.addresses).address;
|
||||
in
|
||||
{
|
||||
# Setup a local DNS server for the NTP domain on the eth1 IP address
|
||||
services.tinydns = {
|
||||
enable = true;
|
||||
ip = eth1IP;
|
||||
data = ''
|
||||
.ntp:${eth1IP}
|
||||
+.${ntpHostname}:${ntpIP}
|
||||
'';
|
||||
};
|
||||
|
||||
# Enable systemd-resolved with DNSSEC and use the local DNS as a name server
|
||||
services.resolved.enable = true;
|
||||
services.resolved.dnssec = "true";
|
||||
networking.nameservers = [ eth1IP ];
|
||||
|
||||
# Configure systemd-timesyncd to use our NTP hostname
|
||||
services.timesyncd.enable = lib.mkForce true;
|
||||
services.timesyncd.servers = [ ntpHostname ];
|
||||
services.timesyncd.extraConfig = ''
|
||||
FallbackNTP=${ntpHostname}
|
||||
'';
|
||||
|
||||
# The debug output is necessary to determine whether systemd-timesyncd successfully resolves our NTP hostname or not
|
||||
systemd.services.systemd-timesyncd.environment.SYSTEMD_LOG_LEVEL = "debug";
|
||||
};
|
||||
|
||||
testScript = ''
|
||||
machine.wait_for_unit("tinydns.service")
|
||||
machine.wait_for_unit("systemd-timesyncd.service")
|
||||
machine.fail("resolvectl query ${ntpHostname}")
|
||||
machine.wait_until_succeeds("journalctl -u systemd-timesyncd.service --grep='Resolved address ${ntpIP}:123 for ${ntpHostname}'")
|
||||
'';
|
||||
})
|
||||
|
|
@ -0,0 +1,46 @@
|
|||
From 7a27556920fe1feefd17096841c8f3ca1294a1b3 Mon Sep 17 00:00:00 2001
|
||||
From: Yuri Nesterov <yuriy.nesterov@unikie.com>
|
||||
Date: Wed, 21 Jun 2023 17:17:38 +0300
|
||||
Subject: [PATCH] timesyncd: disable NSCD when DNSSEC validation is disabled
|
||||
|
||||
Systemd-timesyncd sets SYSTEMD_NSS_RESOLVE_VALIDATE=0 in the unit file
|
||||
to disable DNSSEC validation but it doesn't work when NSCD is used in
|
||||
the system. This patch disabes NSCD in systemd-timesyncd when
|
||||
SYSTEMD_NSS_RESOLVE_VALIDATE is set to 0 so that it uses NSS libraries
|
||||
directly.
|
||||
---
|
||||
src/timesync/timesyncd.c | 11 +++++++++++
|
||||
1 file changed, 11 insertions(+)
|
||||
|
||||
diff --git a/src/timesync/timesyncd.c b/src/timesync/timesyncd.c
|
||||
index 1d8ebecc91..2b0ae361ff 100644
|
||||
--- a/src/timesync/timesyncd.c
|
||||
+++ b/src/timesync/timesyncd.c
|
||||
@@ -21,6 +21,11 @@
|
||||
#include "timesyncd-conf.h"
|
||||
#include "timesyncd-manager.h"
|
||||
#include "user-util.h"
|
||||
+#include "env-util.h"
|
||||
+
|
||||
+struct traced_file;
|
||||
+extern void __nss_disable_nscd(void (*)(size_t, struct traced_file *));
|
||||
+static void register_traced_file(size_t dbidx, struct traced_file *finfo) {}
|
||||
|
||||
static int advance_tstamp(int fd, const struct stat *st) {
|
||||
assert_se(fd >= 0);
|
||||
@@ -198,6 +203,12 @@ static int run(int argc, char *argv[]) {
|
||||
if (r < 0)
|
||||
return log_error_errno(r, "Failed to parse fallback server strings: %m");
|
||||
|
||||
+ r = getenv_bool_secure("SYSTEMD_NSS_RESOLVE_VALIDATE");
|
||||
+ if (r == 0) {
|
||||
+ log_info("Disabling NSCD because DNSSEC validation is turned off");
|
||||
+ __nss_disable_nscd(register_traced_file);
|
||||
+ }
|
||||
+
|
||||
log_debug("systemd-timesyncd running as pid " PID_FMT, getpid_cached());
|
||||
|
||||
notify_message = notify_start("READY=1\n"
|
||||
--
|
||||
2.34.1
|
||||
|
||||
|
|
@ -208,6 +208,7 @@ stdenv.mkDerivation (finalAttrs: {
|
|||
./0017-core-don-t-taint-on-unmerged-usr.patch
|
||||
./0018-tpm2_context_init-fix-driver-name-checking.patch
|
||||
./0019-systemctl-edit-suggest-systemdctl-edit-runtime-on-sy.patch
|
||||
./0020-timesyncd-disable-NSCD-when-DNSSEC-validation-is-dis.patch
|
||||
] ++ lib.optional stdenv.hostPlatform.isMusl (
|
||||
let
|
||||
oe-core = fetchzip {
|
||||
|
|
|
|||
Loading…
Reference in a new issue