[PATCH proxmox-ve-rs v3 2/9] frr: add IPv6 router advertisement support

[Hannes Laimer <h.laimer@proxmox.com>]

Add typed configuration for emitting IPv6 Router Advertisements from
FRR, alongside the existing per-protocol configs. The shape mirrors
the protocol's two layers, keeping interface-level fields separate
from per-prefix flags so neither overloads the other.

Signed-off-by: Hannes Laimer <h.laimer@proxmox.com>
---

Notes:
    v3:
     - keep prefix lifetimes on no-autoconfig prefixes (were dropped)
     - emit ra-interval before ra-lifetime
     - single prefix line instead of duplicated autoconfig branches

 .../templates/frr.conf.jinja                  |  1 +
 .../templates/nd_interfaces.jinja             | 28 +++++++
 proxmox-frr/src/ser/mod.rs                    |  6 ++
 proxmox-frr/src/ser/nd.rs                     | 75 +++++++++++++++++++
 proxmox-frr/src/ser/serializer.rs             |  6 +-
 5 files changed, 115 insertions(+), 1 deletion(-)
 create mode 100644 proxmox-frr-templates/templates/nd_interfaces.jinja
 create mode 100644 proxmox-frr/src/ser/nd.rs

diff --git a/proxmox-frr-templates/templates/frr.conf.jinja b/proxmox-frr-templates/templates/frr.conf.jinja
index 1f98489..8b07088 100644
--- a/proxmox-frr-templates/templates/frr.conf.jinja
+++ b/proxmox-frr-templates/templates/frr.conf.jinja
@@ -10,3 +10,4 @@
 {% include "route_maps.jinja" %}
 {% include "ip_routes.jinja" %}
 {% include "protocol_routemaps.jinja" %}
+{% include "nd_interfaces.jinja" %}
diff --git a/proxmox-frr-templates/templates/nd_interfaces.jinja b/proxmox-frr-templates/templates/nd_interfaces.jinja
new file mode 100644
index 0000000..dd047a9
--- /dev/null
+++ b/proxmox-frr-templates/templates/nd_interfaces.jinja
@@ -0,0 +1,28 @@
+{% for name, iface in nd_interfaces|items %}
+!
+interface {{ name }}
+ no ipv6 nd suppress-ra
+{% if iface.managed_config_flag %}
+ ipv6 nd managed-config-flag
+{% endif %}
+{% if iface.other_config_flag %}
+ ipv6 nd other-config-flag
+{% endif %}
+{% if iface.interval is not none %}
+ ipv6 nd ra-interval {{ iface.interval }}
+{% endif %}
+{% if iface.router_lifetime is not none %}
+ ipv6 nd ra-lifetime {{ iface.router_lifetime }}
+{% endif %}
+{% if iface.mtu is not none %}
+ ipv6 nd mtu {{ iface.mtu }}
+{% endif %}
+{% for rdnss in iface.rdnss %}
+ ipv6 nd rdnss {{ rdnss }}
+{% endfor %}
+{% for prefix in iface.prefixes %}
+ ipv6 nd prefix {{ prefix.cidr }} {{ prefix.valid }} {{ prefix.preferred }}{% if not prefix.autonomous %} no-autoconfig{% endif %}{% if not prefix.on_link %} off-link{% endif %}
+
+{% endfor %}
+exit
+{% endfor %}
diff --git a/proxmox-frr/src/ser/mod.rs b/proxmox-frr/src/ser/mod.rs
index b651121..a65ee46 100644
--- a/proxmox-frr/src/ser/mod.rs
+++ b/proxmox-frr/src/ser/mod.rs
@@ -1,5 +1,6 @@
 pub mod bgp;
 pub mod isis;
+pub mod nd;
 pub mod openfabric;
 pub mod ospf;
 pub mod route_map;
@@ -234,6 +235,11 @@ pub struct FrrConfig {
     #[serde(default)]
     pub prefix_lists: BTreeMap<PrefixListName, Vec<PrefixListRule>>,
 
+    /// `interface <name> / ipv6 nd ...` blocks emitted for subnets with Router
+    /// Advertisements enabled. Presence of an entry implies `no ipv6 nd suppress-ra`.
+    #[serde(default)]
+    pub nd_interfaces: BTreeMap<InterfaceName, nd::NdInterface>,
+
     #[serde(default)]
     pub custom_frr_config: Vec<String>,
 }
diff --git a/proxmox-frr/src/ser/nd.rs b/proxmox-frr/src/ser/nd.rs
new file mode 100644
index 0000000..d9c5545
--- /dev/null
+++ b/proxmox-frr/src/ser/nd.rs
@@ -0,0 +1,75 @@
+use std::net::Ipv6Addr;
+
+use proxmox_network_types::ip_address::Ipv6Cidr;
+use serde::{Deserialize, Serialize};
+
+fn default_true() -> bool {
+    true
+}
+
+/// A single prefix advertised in Router Advertisements on an interface.
+///
+/// The valid and preferred lifetimes are always emitted; they apply to the prefix
+/// information option independently of the autonomous flag. The caller must ensure
+/// `preferred <= valid`, FRR rejects the prefix otherwise.
+#[derive(Clone, Debug, PartialEq, Eq, Serialize, Deserialize)]
+pub struct NdPrefix {
+    pub cidr: Ipv6Cidr,
+    /// Autonomous (A) flag. Defaults to `true`. Clear to emit the prefix with the
+    /// no-autoconfig modifier so hosts use it for on-link/routing decisions but do not
+    /// derive addresses from it via SLAAC.
+    #[serde(
+        default = "default_true",
+        deserialize_with = "proxmox_serde::perl::deserialize_bool"
+    )]
+    pub autonomous: bool,
+    /// On-link (L) flag. Defaults to `true`. Clear to emit the prefix with the off-link
+    /// modifier so hosts reach addresses in the prefix only via the router rather than
+    /// directly on the link.
+    #[serde(
+        default = "default_true",
+        deserialize_with = "proxmox_serde::perl::deserialize_bool"
+    )]
+    pub on_link: bool,
+    /// Valid lifetime (seconds) of the prefix information.
+    #[serde(deserialize_with = "proxmox_serde::perl::deserialize_u32")]
+    pub valid: u32,
+    /// Preferred lifetime (seconds) of the prefix information. Must not exceed `valid`.
+    #[serde(deserialize_with = "proxmox_serde::perl::deserialize_u32")]
+    pub preferred: u32,
+}
+
+/// IPv6 Neighbor Discovery / Router Advertisement configuration for an interface.
+///
+/// Presence of an [`NdInterface`] for an interface implies RAs are enabled on it
+/// (i.e. the generated config emits `no ipv6 nd suppress-ra`). The remaining fields map
+/// 1:1 to FRR `ipv6 nd ...` interface commands.
+#[derive(Clone, Debug, Default, PartialEq, Eq, Serialize, Deserialize)]
+pub struct NdInterface {
+    /// Sets the `M` bit in emitted RAs. Guests should obtain addresses via DHCPv6.
+    #[serde(default, deserialize_with = "proxmox_serde::perl::deserialize_bool")]
+    pub managed_config_flag: bool,
+    /// Sets the `O` bit in emitted RAs. Guests should obtain other configuration via DHCPv6.
+    #[serde(default, deserialize_with = "proxmox_serde::perl::deserialize_bool")]
+    pub other_config_flag: bool,
+    /// RDNSS entries to advertise. Each produces its own `ipv6 nd rdnss <addr>` line.
+    #[serde(default)]
+    pub rdnss: Vec<Ipv6Addr>,
+    /// Default-router lifetime (seconds) advertised in RAs. `0` tells hosts the emitter is not
+    /// a default router. `None` lets FRR use its built-in default (1800s).
+    ///
+    /// Rendered after `interval`: FRR validates a non-zero lifetime against the interval
+    /// configured at that point (matching FRR's own config-write order), so a non-zero value
+    /// must be at least `interval` (or 600 if unset).
+    #[serde(default)]
+    pub router_lifetime: Option<u32>,
+    /// Maximum interval between unsolicited RAs (seconds). `None` keeps the FRR default (600s).
+    #[serde(default)]
+    pub interval: Option<u32>,
+    /// MTU advertised in the RA. `None` omits the MTU option from the RA.
+    #[serde(default)]
+    pub mtu: Option<u32>,
+    /// Prefix advertisements emitted on this interface, in declaration order.
+    #[serde(default)]
+    pub prefixes: Vec<NdPrefix>,
+}
diff --git a/proxmox-frr/src/ser/serializer.rs b/proxmox-frr/src/ser/serializer.rs
index 2ac85d8..5b5d5a5 100644
--- a/proxmox-frr/src/ser/serializer.rs
+++ b/proxmox-frr/src/ser/serializer.rs
@@ -5,7 +5,7 @@ use crate::ser::FrrConfig;
 use proxmox_sortable_macro::sortable;
 
 #[sortable]
-pub static TEMPLATES: [(&str, &str); 12] = sorted!([
+pub static TEMPLATES: [(&str, &str); 13] = sorted!([
     (
         "fabricd.jinja",
         include_str!("/usr/share/proxmox-frr/templates/fabricd.jinja"),
@@ -50,6 +50,10 @@ pub static TEMPLATES: [(&str, &str); 12] = sorted!([
         "protocol_routemaps.jinja",
         include_str!("/usr/share/proxmox-frr/templates/protocol_routemaps.jinja"),
     ),
+    (
+        "nd_interfaces.jinja",
+        include_str!("/usr/share/proxmox-frr/templates/nd_interfaces.jinja"),
+    ),
     (
         "frr.conf.jinja",
         include_str!("/usr/share/proxmox-frr/templates/frr.conf.jinja"),
-- 
2.47.3