agama-network: add ipv4.link-local for ZeroConf/AutoIP

rust/agama-network/src/model.rs

@@ -871,6 +871,36 @@ impl From<InvalidMacAddress> for zbus::fdo::Error {
     }
 }
 
+#[derive(Debug, Default, Copy, Clone, PartialEq, Deserialize, Serialize, utoipa::ToSchema)]
+#[serde(rename_all = "camelCase")]
+pub enum LinkLocal {
+    #[default]
+    Default = 0,
+    Auto = 1,
+    Disabled = 2,
+    Enabled = 3,
+    Fallback = 4,
+}
+
+#[derive(Debug, Error)]
+#[error("Invalid link-local value: {0}")]
+pub struct InvalidLinkLocalValue(i32);
+
+impl TryFrom<i32> for LinkLocal {
+    type Error = InvalidLinkLocalValue;
+
+    fn try_from(value: i32) -> Result<Self, Self::Error> {
+        match value {
+            0 => Ok(LinkLocal::Default),
+            1 => Ok(LinkLocal::Auto),
+            2 => Ok(LinkLocal::Disabled),
+            3 => Ok(LinkLocal::Enabled),
+            4 => Ok(LinkLocal::Fallback),
+            _ => Err(InvalidLinkLocalValue(value)),
+        }
+    }
+}
+
 #[skip_serializing_none]
 #[derive(Default, Debug, PartialEq, Clone, Deserialize, Serialize, utoipa::ToSchema)]
 #[serde(rename_all = "camelCase")]
@@ -899,6 +929,7 @@ pub struct IpConfig {
     pub ip6_privacy: Option<i32>,
     pub dns_priority4: Option<i32>,
     pub dns_priority6: Option<i32>,
+    pub link_local4: LinkLocal,
 }
 
 #[skip_serializing_none]

rust/agama-network/src/nm/dbus.rs

@@ -434,12 +434,21 @@ fn ip_config_to_ipv4_dbus<'a>(
         .collect::<Vec<_>>()
         .into();
 
+    let link_local = if ip_config.link_local4 == LinkLocal::Fallback
+        && VersionReq::parse("<1.52.0").unwrap().matches(nm_version)
+    {
+        LinkLocal::Enabled
+    } else {
+        ip_config.link_local4
+    };
+
     let mut ipv4_dbus = HashMap::from([
         ("address-data", address_data),
         ("dns-data", dns_data),
         ("dns-search", ip_config.dns_searchlist.clone().into()),
         ("ignore-auto-dns", ip_config.ignore_auto_dns.into()),
         ("method", ip_config.method4.to_string().into()),
+        ("link-local", (link_local as i32).into()),
     ]);
 
     if !ip_config.routes4.is_empty() {
@@ -1081,6 +1090,10 @@ fn ip_config_from_dbus(conn: &OwnedNestedHash) -> Result<IpConfig, NmError> {
             ip_config.dns_priority4 = Some(dns_priority4);
         }
 
+        if let Some(link_local4) = get_optional_property::<i32>(ipv4, "link-local")? {
+            ip_config.link_local4 = link_local4.try_into().unwrap_or_default();
+        }
+
         let mut dhcp4_settings = Dhcp4Settings::default();
         if let Some(dhcp_send_hostname) = get_optional_property(ipv4, "dhcp-send-hostname-v2")? {
             dhcp4_settings.send_hostname = match dhcp_send_hostname {

rust/agama-server/src/web/docs/network.rs

@@ -110,6 +110,7 @@ impl ApiDocBuilder for NetworkApiDocBuilder {
             .schema_from::<agama_lib::network::model::DhcpIaid>()
             .schema_from::<agama_lib::network::model::Dhcp6Settings>()
             .schema_from::<agama_lib::network::model::DhcpDuid>()
+            .schema_from::<agama_lib::network::model::LinkLocal>()
             .schema_from::<crate::network::web::PersistParams>()
             .schema("IpAddr", schemas::ip_addr())
             .schema("IpInet", schemas::ip_inet())

rust/package/agama.changes

@@ -1,3 +1,9 @@
+-------------------------------------------------------------------
+Tue Oct  7 09:55:46 UTC 2025 - Clemens Famulla-Conrad <cfamullaconrad@suse.com>
+
+- Add IpConfig.link_local4 to specify ZeroConf/AutoIP behavior.
+  (gh#agama-project/agama#2792).
+
 -------------------------------------------------------------------
 Wed Oct  1 13:45:23 UTC 2025 - Ladislav Slezák <lslezak@suse.com>