From: Yu Watanabe <watanabe.yu+github@gmail.com>
Date: Thu, 27 Jan 2022 18:50:16 +0000 (+0900)
Subject: sd-dhcp-server: do not assign an address from pool when a static lease for the client... 
X-Git-Tag: v251-rc1~396^2~10
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=e2ba408084935fffa0c73007528de7babf9309c8;p=thirdparty%2Fsystemd.git

sd-dhcp-server: do not assign an address from pool when a static lease for the client ID exists
---

diff --git a/src/libsystemd-network/sd-dhcp-server.c b/src/libsystemd-network/sd-dhcp-server.c
index 820bec888eb..ddcd6910e90 100644
--- a/src/libsystemd-network/sd-dhcp-server.c
+++ b/src/libsystemd-network/sd-dhcp-server.c
@@ -1091,9 +1091,13 @@ int dhcp_server_handle_message(sd_dhcp_server *server, DHCPMessage *message, siz
                 if (address == server->address)
                         return 0;
 
-                /* verify that the requested address is from the pool, and either
-                   owned by the current client or free */
-                if (static_lease && static_lease->address == address) {
+                if (static_lease) {
+                        /* Found a static lease for the client ID. */
+
+                        if (static_lease->address != address)
+                                /* The client requested an address which is different from the static lease. Refuse. */
+                                return server_send_nak_or_ignore(server, init_reboot, req);
+
                         _cleanup_(dhcp_lease_freep) DHCPLease *lease = NULL;
                         usec_t time_now, expiration;