libvirt/network-don-t-use-dhcp-authoritative-on-static-netwo.patch

From ec5427d1007477b746dde3ba24b7951a6e14a3d7 Mon Sep 17 00:00:00 2001
From: Jim Fehlig <jfehlig@suse.com>
Date: Tue, 5 Jul 2022 11:19:41 -0600
Subject: network: don't use dhcp-authoritative on static networks

"Static" DHCP networks are those where no dynamic DHCP range is
defined, only a list of host entries is used to serve permanent
IP addresses. On such networks, we don't want dnsmasq to reply
to other requests than those statically defined. But
"dhcp-authoritative" will cause dnsmasq to do just that.
Therefore we can't use "dhcp-authoritative" for static networks.

Fixes: 4ac20b3ae "network: add dnsmasq option 'dhcp-authoritative'"
Signed-off-by: Martin Wilck <mwilck@suse.com>
---
 src/network/bridge_driver.c                             | 9 ++++++++-
 tests/networkxml2confdata/dhcp6host-routed-network.conf | 1 -
 2 files changed, 8 insertions(+), 2 deletions(-)

Index: libvirt-8.10.0/src/network/bridge_driver.c
===================================================================
--- libvirt-8.10.0.orig/src/network/bridge_driver.c
+++ libvirt-8.10.0/src/network/bridge_driver.c
@@ -1044,7 +1044,14 @@ networkDnsmasqConfDHCP(virBuffer *buf,
     if (VIR_SOCKET_ADDR_IS_FAMILY(&ipdef->address, AF_INET)) {
         if (ipdef->nranges || ipdef->nhosts) {
             virBufferAddLit(buf, "dhcp-no-override\n");
-            virBufferAddLit(buf, "dhcp-authoritative\n");
+            /*
+             * Use "dhcp-authoritative" only for dynamic DHCP.
+             * In a static-only network, it would cause dnsmasq
+             * to reply to requests from other hosts than those
+             * statically defined.
+             */
+            if (ipdef->nranges || !ipdef->nhosts)
+                virBufferAddLit(buf, "dhcp-authoritative\n");
         }
 
         if (ipdef->bootfile) {
Index: libvirt-8.10.0/tests/networkxml2confdata/dhcp6host-routed-network.conf
===================================================================
--- libvirt-8.10.0.orig/tests/networkxml2confdata/dhcp6host-routed-network.conf
+++ libvirt-8.10.0/tests/networkxml2confdata/dhcp6host-routed-network.conf
@@ -10,7 +10,6 @@ bind-dynamic
 interface=virbr1
 dhcp-range=192.168.122.1,static
 dhcp-no-override
-dhcp-authoritative
 dhcp-range=2001:db8:ac10:fd01::1,static,64
 dhcp-hostsfile=/var/lib/libvirt/dnsmasq/local.hostsfile
 addn-hosts=/var/lib/libvirt/dnsmasq/local.addnhosts