[PATCH network v5 04/10] sdn: simple: enable force_forwarding for ipv6 forwarding to subnets

[Lukas Sichert <l.sichert@proxmox.com>]

Simple zones can route ipv6 subnet traffic through a VNet bridge. Until
now, this depended on global ipv6 forwarding state, which also changes
Router Advertisement handling for the whole host.

Enable 'force_forwarding' explicitly on the Subnet bridge using the
'ip6-force-forward' ifupdown2 flag.

Signed-off-by: Lukas Sichert <l.sichert@proxmox.com>
---
 src/PVE/Network/SDN/Zones/SimplePlugin.pm              | 6 +++++-
 src/test/zones/simple/ipv4v6/expected_sdn_interfaces   | 1 +
 src/test/zones/simple/ipv6snat/expected_sdn_interfaces | 1 +
 3 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/src/PVE/Network/SDN/Zones/SimplePlugin.pm b/src/PVE/Network/SDN/Zones/SimplePlugin.pm
index 347eee9..db605cc 100644
--- a/src/PVE/Network/SDN/Zones/SimplePlugin.pm
+++ b/src/PVE/Network/SDN/Zones/SimplePlugin.pm
@@ -149,7 +149,11 @@ sub generate_sdn_config {
     push @iface_config, "mtu $mtu" if $mtu;
     push @iface_config, "alias $alias" if $alias;
     push @iface_config, "ip-forward on" if $enable_forward_v4;
-    push @iface_config, "ip6-forward on" if $enable_forward_v6;
+
+    if ($enable_forward_v6) {
+        push @iface_config, "ip6-forward on";
+        push @iface_config, 'ip6-force-forward on';
+    }
 
     push @{ $config->{$vnetid} }, @iface_config;
 
diff --git a/src/test/zones/simple/ipv4v6/expected_sdn_interfaces b/src/test/zones/simple/ipv4v6/expected_sdn_interfaces
index 34ed5db..4b02ce3 100644
--- a/src/test/zones/simple/ipv4v6/expected_sdn_interfaces
+++ b/src/test/zones/simple/ipv4v6/expected_sdn_interfaces
@@ -9,3 +9,4 @@ iface myvnet
 	bridge_fd 0
 	ip-forward on
 	ip6-forward on
+	ip6-force-forward on
diff --git a/src/test/zones/simple/ipv6snat/expected_sdn_interfaces b/src/test/zones/simple/ipv6snat/expected_sdn_interfaces
index 5f6d40b..38393fd 100644
--- a/src/test/zones/simple/ipv6snat/expected_sdn_interfaces
+++ b/src/test/zones/simple/ipv6snat/expected_sdn_interfaces
@@ -11,3 +11,4 @@ iface myvnet
 	bridge_stp off
 	bridge_fd 0
 	ip6-forward on
+	ip6-force-forward on
-- 
2.47.3