nm: Preserve current IP setting for multiconnect profile

Given a interface is activated by a NM profile of multiconnect,
When applying empty state for this interface,
Then this interface will get IPv4 and IPv6 disabled.

This is because current nmstate code treat multiconnect or NM connection
without interface name as not matched, hence `exist_nm_conn` is set to
None which lead to nmstate discarding current IP settings.

Cloning multiconnect profiles could have risk when NM added more
properties impacting activation but nmstate not aware.

Hence we create NM connection from scratch in this case by only
preserving IP settings from multiconnect. Other non-ip settings applied
by multiconnect profile will be discard if not mentioned in desired
state.

Integration test case included.

Resolves: https://issues.redhat.com/browse/RHEL-61890

Signed-off-by: Gris Ge <[email protected]>

rust/src/lib/nm/settings/connection.rs

@@ -43,31 +43,33 @@ pub(crate) fn iface_to_nm_connections(
 ) -> Result<Vec<NmConnection>, NmstateError> {
     let mut ret: Vec<NmConnection> = Vec::new();
 
-    let iface = if let Some(i) = merged_iface.for_apply.as_ref() {
-        i
+    let mut iface = if let Some(i) = merged_iface.for_apply.as_ref() {
+        i.clone()
     } else {
         return Ok(ret);
     };
 
-    let base_iface = iface.base_iface();
-    let exist_nm_conn =
-        if base_iface.identifier == Some(InterfaceIdentifier::MacAddress) {
-            get_exist_profile_by_profile_name(
-                exist_nm_conns,
-                base_iface
-                    .profile_name
-                    .as_deref()
-                    .unwrap_or(base_iface.name.as_str()),
-                &base_iface.iface_type,
-            )
-        } else {
-            get_exist_profile(
-                exist_nm_conns,
-                &base_iface.name,
-                &base_iface.iface_type,
-                nm_ac_uuids,
-            )
-        };
+    let exist_nm_conn = if iface.base_iface().identifier
+        == Some(InterfaceIdentifier::MacAddress)
+    {
+        get_exist_profile_by_profile_name(
+            exist_nm_conns,
+            iface
+                .base_iface()
+                .profile_name
+                .as_deref()
+                .unwrap_or(iface.base_iface().name.as_str()),
+            &iface.base_iface().iface_type,
+        )
+    } else {
+        get_exist_profile(
+            exist_nm_conns,
+            &iface.base_iface().name,
+            &iface.base_iface().iface_type,
+            nm_ac_uuids,
+        )
+    };
+
     if iface.is_up_exist_config() {
         if let Some(nm_conn) = exist_nm_conn {
             if !iface.is_userspace()
@@ -102,6 +104,16 @@ pub(crate) fn iface_to_nm_connections(
             }
         }
     }
+
+    // If exist_nm_conn is None and desired state did not mention IP settings,
+    // we are supported to preserve current IP state instead of setting ipv4 and
+    // ipv6 disabled.
+    if exist_nm_conn.is_none() {
+        preserve_current_ip(&mut iface, merged_iface.current.as_ref());
+    }
+
+    let iface = &iface;
+
     let mut nm_conn = exist_nm_conn.cloned().unwrap_or_default();
     nm_conn.flags = Vec::new();
 
@@ -243,8 +255,8 @@ pub(crate) fn iface_to_nm_connections(
     }
 
     if let (Some(ctrl), Some(ctrl_type)) = (
-        base_iface.controller.as_ref(),
-        base_iface.controller_type.as_ref(),
+        iface.base_iface().controller.as_ref(),
+        iface.base_iface().controller_type.as_ref(),
     ) {
         if let Some(ctrl_iface) =
             merged_state.interfaces.get_iface(ctrl, ctrl_type.clone())
@@ -307,7 +319,7 @@ pub(crate) fn iface_to_nm_connections(
 
     // When detaching a OVS system interface from OVS bridge, we should remove
     // its NmSettingOvsIface setting
-    if base_iface.controller.as_deref() == Some("") {
+    if iface.base_iface().controller.as_deref() == Some("") {
         nm_conn.ovs_iface = None;
     }
 
@@ -545,3 +557,14 @@ fn persisten_iface_cur_conf(
         gen_conf_mode,
     )
 }
+
+fn preserve_current_ip(iface: &mut Interface, cur_iface: Option<&Interface>) {
+    if iface.base_iface().ipv4.is_none() {
+        iface.base_iface_mut().ipv4 =
+            cur_iface.as_ref().and_then(|i| i.base_iface().ipv4.clone());
+    }
+    if iface.base_iface().ipv6.is_none() {
+        iface.base_iface_mut().ipv6 =
+            cur_iface.as_ref().and_then(|i| i.base_iface().ipv6.clone());
+    }
+}

tests/integration/nm/profile_test.py

@@ -676,3 +676,39 @@ def test_change_profile_name(eth1_up):
         ].strip()
         == "eth1-new"
     )
+
+
+@pytest.fixture
+def multiconnect_profile_with_ip_enabled(eth1_up):
+    cmdlib.exec_cmd("nmcli c del eth1".split(), check=True)
+    cmdlib.exec_cmd(
+        "nmcli c add type ethernet connection.id nmstate-test-default "
+        "connection.multi-connect multiple "
+        "ipv4.method auto ipv6.method auto".split(),
+        check=True,
+    )
+    yield
+    cmdlib.exec_cmd("nmcli c del nmstate-test-default".split(), check=False)
+
+
+def test_preserve_ip_settings_from_multiconnect(
+    multiconnect_profile_with_ip_enabled,
+):
+    desired_state = {
+        Interface.KEY: [
+            {
+                Interface.NAME: "eth1",
+                Interface.TYPE: InterfaceType.ETHERNET,
+                Interface.STATE: InterfaceState.UP,
+            }
+        ]
+    }
+    libnmstate.apply(desired_state)
+    assert (
+        cmdlib.exec_cmd("nmcli -g ipv4.method c show eth1".split())[1].strip()
+        == "auto"
+    )
+    assert (
+        cmdlib.exec_cmd("nmcli -g ipv6.method c show eth1".split())[1].strip()
+        == "auto"
+    )