nm ip: fix ipv4.dhcp-timeout even when ip not desired

When a NM connection holding non-infinity `ipv4.dhcp-timeout`, the
connection will be deactivated on DHCP timeout, when nmstate modifying
this NM connection, it should also fix `ipv4.dhcp-timeout` to make sure
it never been deactivated due to timeout even when ipv4 not mentioned in
desired state.

This patch will always set `ipv4.dhcp-timeout` and `ipv6.dhcp-timeout`
to `i32::MAX` for NM connections we are about to modify.

Integration test case include.

Resolves: https://issues.redhat.com/browse/RHEL-16865

Signed-off-by: Gris Ge <fge@redhat.com>

rust/src/lib/nm/profile.rs

@@ -2,8 +2,9 @@
 
 use super::nm_dbus::{NmActiveConnection, NmConnection};
 use super::settings::{
-    get_exist_profile, iface_to_nm_connections, remove_nm_mptcp_set,
-    use_uuid_for_controller_reference, use_uuid_for_parent_reference,
+    fix_ip_dhcp_timeout, get_exist_profile, iface_to_nm_connections,
+    remove_nm_mptcp_set, use_uuid_for_controller_reference,
+    use_uuid_for_parent_reference,
 };
 
 use crate::{
@@ -118,6 +119,8 @@ pub(crate) fn perpare_nm_conns(
         }
     }
 
+    fix_ip_dhcp_timeout(&mut nm_conns_to_update);
+
     use_uuid_for_controller_reference(
         &mut nm_conns_to_update,
         &merged_state.interfaces,

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

@@ -343,3 +343,17 @@ fn apply_nmstate_wait_ip(
         None => (),
     }
 }
+
+// Even user not desired IP section changes, we should set ipv4.dhcp_timeout
+// and ipv6.dhcp_timeout to i32::MAX to make sure NetworkManager never
+// deactivate a desired interface
+pub(crate) fn fix_ip_dhcp_timeout(nm_conns: &mut [NmConnection]) {
+    for nm_conn in nm_conns {
+        if let Some(nm_ip_set) = nm_conn.ipv4.as_mut() {
+            nm_ip_set.dhcp_timeout = Some(i32::MAX);
+        }
+        if let Some(nm_ip_set) = nm_conn.ipv6.as_mut() {
+            nm_ip_set.dhcp_timeout = Some(i32::MAX);
+        }
+    }
+}

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

@@ -42,6 +42,7 @@ pub(crate) use self::connection::{
 pub(crate) use self::inter_connections::{
     use_uuid_for_controller_reference, use_uuid_for_parent_reference,
 };
+pub(crate) use self::ip::fix_ip_dhcp_timeout;
 
 #[cfg(feature = "query_apply")]
 pub(crate) use self::bond::get_bond_balance_slb;

tests/integration/nm/ip_test.py

@@ -19,6 +19,8 @@ IPV6_ADDRESS1 = "2001:db8:1::1"
 IPV6_ADDRESS2 = "2001:db8:1::2"
 IPV6_NET1 = "2001:db8:a::/64"
 
+I32_MAX = 0x7FFFFFFF
+
 
 def test_get_applied_config_for_dhcp_state_with_dhcp_enabeld_on_disk(eth1_up):
     iface_state = eth1_up[Interface.KEY][0]
@@ -184,3 +186,40 @@ def test_switch_static_gateway_to_dhcp(eth1_up_with_nm_gateway):
         cmdlib.exec_cmd("nmcli -g ipv6.gateway c show eth1".split())[1].strip()
         == ""
     )
+
+
+@pytest.fixture
+def dummy1_with_small_dhcp_timeout():
+    cmdlib.exec_cmd(
+        "nmcli c add type dummy ifname dummy1 connection.id dummy1 "
+        "ipv4.method auto ipv4.dhcp-timeout 5 "
+        "ipv6.method auto ipv6.dhcp-timeout 5 ".split(),
+        check=True,
+    )
+    yield
+    cmdlib.exec_cmd("nmcli c del dummy1".split(), check=True)
+
+
+def test_fix_dhcp_timeout_even_not_desired(dummy1_with_small_dhcp_timeout):
+    iface_state = {
+        Interface.NAME: "dummy1",
+        Interface.DESCRIPTION: "test_only",
+    }
+    libnmstate.apply({Interface.KEY: [iface_state]})
+
+    assert (
+        int(
+            cmdlib.exec_cmd(
+                "nmcli -g ipv4.dhcp-timeout c show dummy1".split()
+            )[1].strip()
+        )
+        == I32_MAX
+    )
+    assert (
+        int(
+            cmdlib.exec_cmd(
+                "nmcli -g ipv6.dhcp-timeout c show dummy1".split()
+            )[1].strip()
+        )
+        == I32_MAX
+    )