dhcpd: reply with NAK to clients in INIT-REBOOT state w/o existing lease

We were not responding to them at all.

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 11 insertions, 7 deletions

diff --git a/networking/udhcp/dhcpd.c b/networking/udhcp/dhcpd.c
index ac77b511d..6fb48a19a 100644
--- a/networking/udhcp/dhcpd.c
+++ b/networking/udhcp/dhcpd.c
@@ -448,9 +448,9 @@ int udhcpd_main(int argc UNUSED_PARAM, char **argv)
                 /* Get SERVER_ID if present */
                 server_id_opt = udhcp_get_option(&packet, DHCP_SERVER_ID);
                 if (server_id_opt) {
-                        uint32_t server_id_net;
-                        move_from_unaligned32(server_id_net, server_id_opt);
-                        if (server_id_net != server_config.server_nip) {
+                        uint32_t server_id_network_order;
+                        move_from_unaligned32(server_id_network_order, server_id_opt);
+                        if (server_id_network_order != server_config.server_nip) {
                                 /* client talks to somebody else */
                                 log1("server ID doesn't match, ignoring");
                                 continue;
@@ -584,11 +584,15 @@ o DHCPREQUEST generated during REBINDING state:
                                 send_ACK(&packet, lease->lease_nip);
                                 break;
                         }
-                        if (server_id_opt) {
-                                /* client was talking specifically to us.
-                                 * "No, we don't have this IP for you". */
+                        /* No lease for this MAC, or lease IP != requested IP */
+
+                        if (server_id_opt    /* client is in SELECTING state */
+                         || requested_ip_opt /* client is in INIT-REBOOT state */
+                        ) {
+                                /* "No, we don't have this IP for you" */
                                 send_NAK(&packet);
-                        }
+                        } /* else: client is in RENEWING or REBINDING, do not answer */
+
                         break;
 
                 case DHCPDECLINE: