gw: Validate IP is within client_ip_range in valid_ip()

When gateway config changes and client_ip_range is modified, existing
CVMs may have IPs outside the new range. The valid_ip() function now
checks if IP is within client_ip_range, causing re-registration to
allocate a new IP within the valid range.

Author: kvinwang

gateway/src/main_service.rs

@@ -782,6 +782,10 @@ fn reload_instances_from_kv_store(proxy: &Proxy, store: &KvStore) -> Result<()>
 
 impl ProxyState {
     fn valid_ip(&self, ip: Ipv4Addr) -> bool {
+        // Must be within client IP range
+        if !self.config.wg.client_ip_range.contains(&ip) {
+            return false;
+        }
         if self.config.wg.ip.broadcast() == ip {
             return false;
         }