forked from rpms/libvirt
153 lines
6.0 KiB
Diff
153 lines
6.0 KiB
Diff
From dc8cf11686c075166a3029e974a6caeefe521d75 Mon Sep 17 00:00:00 2001
|
|
Message-Id: <dc8cf11686c075166a3029e974a6caeefe521d75@dist-git>
|
|
From: Laine Stump <laine@redhat.com>
|
|
Date: Fri, 15 Jan 2021 22:51:50 -0500
|
|
Subject: [PATCH] util: synchronize with firewalld before we start calling
|
|
iptables directly
|
|
|
|
When it is starting up, firewalld will delete all existing iptables
|
|
rules and chains before adding its own rules. If libvirtd were to try
|
|
to directly add iptables rules during the time before firewalld has
|
|
finished initializing, firewalld would end up deleting the rules that
|
|
libvirtd has just added.
|
|
|
|
Currently this isn't a problem, since libvirtd only adds iptables
|
|
rules via the firewalld "passthrough command" API, and so firewalld is
|
|
able to properly serialize everything. However, we will soon be
|
|
changing libvirtd to add its iptables and ebtables rules by directly
|
|
calling iptables/ebtables rather than via firewalld, thus removing the
|
|
serialization of libvirtd adding rules vs. firewalld deleting rules.
|
|
|
|
This will especially apparent (if we don't fix it in advance, as this
|
|
patch does) when libvirtd is responding to the dbus NameOwnerChanged
|
|
event, which is used to learn when firewalld has been restarted. In
|
|
that case, dbus sends the event before firewalld has been able to
|
|
complete its initialization, so when libvirt responds to the event by
|
|
adding back its iptables rules (with direct calls to
|
|
/usr/bin/iptables), some of those rules are added before firewalld has
|
|
a chance to do its "remove everything" startup protocol. The usual
|
|
result of this is that libvirt will successfully add its private
|
|
chains (e.g. LIBVIRT_INP, etc), but then fail when it tries to add a
|
|
rule jumping to one of those chains (because in the interim, firewalld
|
|
has deleted the new chains).
|
|
|
|
The solution is for libvirt to preface it's direct calling to iptables
|
|
with a iptables command sent via firewalld's passthrough command
|
|
API. Since commands sent to firewalld are completed synchronously, and
|
|
since firewalld won't service them until it has completed its own
|
|
initialization, this will assure that by the time libvirt starts
|
|
calling iptables to add rules, that firewalld will not be following up
|
|
by deleting any of those rules.
|
|
|
|
To minimize the amount of extra overhead, we request the simplest
|
|
iptables command possible: "iptables -V" (and aside from logging a
|
|
debug message, we ignore the result, for good measure).
|
|
|
|
(This patch is being done *before* the patch that switches to calling
|
|
iptables directly, so that everything will function properly with any
|
|
fractional part of the series applied).
|
|
|
|
https://bugzilla.redhat.com/1607929
|
|
|
|
Signed-off-by: Laine Stump <laine@redhat.com>
|
|
Reviewed-by: Daniel Henrique Barboza <danielhb413@gmail.com>
|
|
(cherry picked from commit 070690538a1ed301b004c542d94b13ee9bffc9d6)
|
|
|
|
Conflicts: src/util/viriptables.c:
|
|
one line of code in context moved during g_autoptr conversion.
|
|
Signed-off-by: Laine Stump <laine@redhat.com>
|
|
Message-Id: <20210116035151.1066734-8-laine@redhat.com>
|
|
Reviewed-by: Jiri Denemark <jdenemar@redhat.com>
|
|
---
|
|
src/libvirt_private.syms | 1 +
|
|
src/util/virfirewall.c | 30 ++++++++++++++++++++++++++++++
|
|
src/util/virfirewall.h | 2 ++
|
|
src/util/viriptables.c | 7 +++++++
|
|
4 files changed, 40 insertions(+)
|
|
|
|
diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms
|
|
index edc53ce899..9d87e2a27b 100644
|
|
--- a/src/libvirt_private.syms
|
|
+++ b/src/libvirt_private.syms
|
|
@@ -2080,6 +2080,7 @@ virFileCacheSetPriv;
|
|
# util/virfirewall.h
|
|
virFirewallAddRuleFull;
|
|
virFirewallApply;
|
|
+virFirewallBackendSynchronize;
|
|
virFirewallFree;
|
|
virFirewallNew;
|
|
virFirewallRemoveRule;
|
|
diff --git a/src/util/virfirewall.c b/src/util/virfirewall.c
|
|
index 520d515c11..66d20d3f17 100644
|
|
--- a/src/util/virfirewall.c
|
|
+++ b/src/util/virfirewall.c
|
|
@@ -653,6 +653,36 @@ virFirewallApplyRuleFirewallD(virFirewallRulePtr rule,
|
|
return virFirewallDApplyRule(rule->layer, rule->args, rule->argsLen, ignoreErrors, output);
|
|
}
|
|
|
|
+
|
|
+void
|
|
+virFirewallBackendSynchronize(void)
|
|
+{
|
|
+ const char *arg = "-V";
|
|
+ g_autofree char *output = NULL;
|
|
+
|
|
+ switch (currentBackend) {
|
|
+ case VIR_FIREWALL_BACKEND_DIRECT:
|
|
+ /* nobody to synchronize with */
|
|
+ break;
|
|
+ case VIR_FIREWALL_BACKEND_FIREWALLD:
|
|
+ /* Send a simple rule via firewalld's passthrough iptables
|
|
+ * command so that we'll be sure firewalld has fully
|
|
+ * initialized and caught up with its internal queue of
|
|
+ * iptables commands. Waiting for this will prevent our own
|
|
+ * directly-executed iptables commands from being run while
|
|
+ * firewalld is still initializing.
|
|
+ */
|
|
+ ignore_value(virFirewallDApplyRule(VIR_FIREWALL_LAYER_IPV4,
|
|
+ (char **)&arg, 1, true, &output));
|
|
+ VIR_DEBUG("Result of 'iptables -V' via firewalld: %s", NULLSTR(output));
|
|
+ break;
|
|
+ case VIR_FIREWALL_BACKEND_AUTOMATIC:
|
|
+ case VIR_FIREWALL_BACKEND_LAST:
|
|
+ break;
|
|
+ }
|
|
+}
|
|
+
|
|
+
|
|
static int
|
|
virFirewallApplyRule(virFirewallPtr firewall,
|
|
virFirewallRulePtr rule,
|
|
diff --git a/src/util/virfirewall.h b/src/util/virfirewall.h
|
|
index fda3cdec01..3db0864380 100644
|
|
--- a/src/util/virfirewall.h
|
|
+++ b/src/util/virfirewall.h
|
|
@@ -111,4 +111,6 @@ void virFirewallStartRollback(virFirewallPtr firewall,
|
|
|
|
int virFirewallApply(virFirewallPtr firewall);
|
|
|
|
+void virFirewallBackendSynchronize(void);
|
|
+
|
|
G_DEFINE_AUTOPTR_CLEANUP_FUNC(virFirewall, virFirewallFree);
|
|
diff --git a/src/util/viriptables.c b/src/util/viriptables.c
|
|
index 6b3a025880..41544b7f36 100644
|
|
--- a/src/util/viriptables.c
|
|
+++ b/src/util/viriptables.c
|
|
@@ -154,6 +154,13 @@ iptablesSetupPrivateChains(virFirewallLayer layer)
|
|
|
|
fw = virFirewallNew();
|
|
|
|
+ /* When the backend is firewalld, we need to make sure that
|
|
+ * firewalld has been fully started and completed its
|
|
+ * initialization, otherwise firewalld might delete our rules soon
|
|
+ * after we add them!
|
|
+ */
|
|
+ virFirewallBackendSynchronize();
|
|
+
|
|
virFirewallStartTransaction(fw, 0);
|
|
|
|
for (i = 0; i < G_N_ELEMENTS(data); i++)
|
|
--
|
|
2.30.0
|
|
|