ctdb-scripts: Avoid failing updateip when IP is not assigned

There is no use failing this when it could behave more like takeip.

Use old interface of "__none__" as a hint that ctdbd doesn't think the
IP is assigned either.  In this case print a warning instead of an
error.  Take some care to avoid spurious errors in updateip.

After commit 0536d7a (which improves
IP address state checking), this will almost certainly not occur on
platforms with getifaddrs(3) (e.g. Linux).  This means it is only
likely to occur in 4.21 when net.ipv4.ip_nonlocal_bind=1.

Update test to match.

BUG: https://bugzilla.samba.org/show_bug.cgi?id=15935

Reported-by: Bailey Allison <[email protected]>
Signed-off-by: Martin Schwenke <[email protected]>
Reviewed-by: Anoop C S <[email protected]>

Autobuild-User(master): Anoop C S <[email protected]>
Autobuild-Date(master): Fri Oct 17 06:28:30 UTC 2025 on atb-devel-224

Author: mschwenke-ddn

ctdb/config/events/legacy/10.interface.script

@@ -78,6 +78,11 @@ get_iface_ip_maskbits()
 				"$ip" "$maskbits" "$_maskbits_in"
 		fi
 	else
+		if [ "$_iface_in" = "__none__" ]; then
+			echo "WARNING: Unable to determine interface for IP ${ip}"
+			iface="$_iface_in"
+			return
+		fi
 		die "ERROR: Unable to determine interface for IP ${ip}"
 	fi
 }
@@ -214,10 +219,14 @@ updateip)
 		exit 0
 	fi
 
-	ip_block "$ip" "$oiface"
-
-	delete_ip_from_iface "$oiface" "$ip" "$maskbits" 2>/dev/null
-	delete_ip_from_iface "$niface" "$ip" "$maskbits" 2>/dev/null
+	# Behave more like takeip when the IP is not assigned.  No
+	# need for a similar condition around ip_unblock()s because
+	# they will silently fail.
+	if [ "$oiface" != "__none__" ]; then
+		ip_block "$ip" "$oiface"
+		delete_ip_from_iface "$oiface" "$ip" "$maskbits" >/dev/null 2>&1
+	fi
+	delete_ip_from_iface "$niface" "$ip" "$maskbits" >/dev/null 2>&1
 
 	add_ip_to_iface "$niface" "$ip" "$maskbits" || {
 		ip_unblock "$ip" "$oiface"

ctdb/tests/UNIT/eventscripts/10.interface.updateip.001.sh

@@ -10,7 +10,7 @@ public_address=$(ctdb_get_1_public_address)
 ip="${public_address% *}"
 ip="${ip#* }"
 
-required_result 1 "ERROR: Unable to determine interface for IP ${ip}"
+ok "WARNING: Unable to determine interface for IP ${ip}"
 # Want separate words from public_address: interface IP maskbits
 # shellcheck disable=SC2086
 simple_test "__none__" $public_address