1 files changed, 30 insertions, 26 deletions

diff --git a/networking/udhcp/dhcpd.c b/networking/udhcp/dhcpd.c
index a015cf038..ac77b511d 100644
--- a/networking/udhcp/dhcpd.c
+++ b/networking/udhcp/dhcpd.c
@@ -133,7 +133,10 @@ static uint32_t select_lease_time(struct dhcp_packet *packet)
 
 /* We got a DHCP DISCOVER. Send an OFFER. */
 /* NOINLINE: limit stack usage in caller */
-static NOINLINE void send_offer(struct dhcp_packet *oldpacket, uint32_t static_lease_nip, struct dyn_lease *lease)
+static NOINLINE void send_offer(struct dhcp_packet *oldpacket,
+                uint32_t static_lease_nip,
+                struct dyn_lease *lease,
+                uint8_t *requested_ip_opt)
 {
         struct dhcp_packet packet;
         uint32_t lease_time_sec;
@@ -147,7 +150,6 @@ static NOINLINE void send_offer(struct dhcp_packet *oldpacket, uint32_t static_l
         if (!static_lease_nip) {
                 /* We have no static lease for client's chaddr */
                 uint32_t req_nip;
-                uint8_t *req_ip_opt;
                 const char *p_host_name;
 
                 if (lease) {
@@ -158,9 +160,9 @@ static NOINLINE void send_offer(struct dhcp_packet *oldpacket, uint32_t static_l
                         packet.yiaddr = lease->lease_nip;
                 }
                 /* Or: if client has requested an IP */
-                else if ((req_ip_opt = udhcp_get_option(oldpacket, DHCP_REQUESTED_IP)) != NULL
+                else if (requested_ip_opt != NULL
                  /* (read IP) */
-                 && (move_from_unaligned32(req_nip, req_ip_opt), 1)
+                 && (move_from_unaligned32(req_nip, requested_ip_opt), 1)
                  /* and the IP is in the lease range */
                  && ntohl(req_nip) >= server_config.start_ip
                  && ntohl(req_nip) <= server_config.end_ip
@@ -283,16 +285,12 @@ struct dyn_lease *g_leases;
 int udhcpd_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 int udhcpd_main(int argc UNUSED_PARAM, char **argv)
 {
-        fd_set rfds;
         int server_socket = -1, retval, max_sock;
-        struct dhcp_packet packet;
         uint8_t *state;
-        uint32_t static_lease_nip;
         unsigned timeout_end;
         unsigned num_ips;
         unsigned opt;
         struct option_set *option;
-        struct dyn_lease *lease, fake_lease;
         IF_FEATURE_UDHCP_PORT(char *str_P;)
 
 #if ENABLE_FEATURE_UDHCP_PORT
@@ -372,11 +370,15 @@ int udhcpd_main(int argc UNUSED_PARAM, char **argv)
 
         timeout_end = monotonic_sec() + server_config.auto_time;
         while (1) { /* loop until universe collapses */
+                fd_set rfds;
+                struct dhcp_packet packet;
                 int bytes;
                 struct timeval tv;
                 uint8_t *server_id_opt;
-                uint8_t *requested_opt;
+                uint8_t *requested_ip_opt;
                 uint32_t requested_nip = requested_nip; /* for compiler */
+                uint32_t static_lease_nip;
+                struct dyn_lease *lease, fake_lease;
 
                 if (server_socket < 0) {
                         server_socket = udhcp_listen_socket(/*INADDR_ANY,*/ SERVER_PORT,
@@ -443,6 +445,18 @@ int udhcpd_main(int argc UNUSED_PARAM, char **argv)
                         continue;
                 }
 
+                /* 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) {
+                                /* client talks to somebody else */
+                                log1("server ID doesn't match, ignoring");
+                                continue;
+                        }
+                }
+
                 /* Look for a static/dynamic lease */
                 static_lease_nip = get_static_nip_by_mac(server_config.static_leases, &packet.chaddr);
                 if (static_lease_nip) {
@@ -455,20 +469,10 @@ int udhcpd_main(int argc UNUSED_PARAM, char **argv)
                         lease = find_lease_by_mac(packet.chaddr);
                 }
 
-                /* Get REQUESTED_IP and 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) {
-                                /* client talks to somebody else */
-                                log1("server ID doesn't match, ignoring");
-                                continue;
-                        }
-                }
-                requested_opt = udhcp_get_option(&packet, DHCP_REQUESTED_IP);
-                if (requested_opt) {
-                        move_from_unaligned32(requested_nip, requested_opt);
+                /* Get REQUESTED_IP if present */
+                requested_ip_opt = udhcp_get_option(&packet, DHCP_REQUESTED_IP);
+                if (requested_ip_opt) {
+                        move_from_unaligned32(requested_nip, requested_ip_opt);
                 }
 
                 switch (state[0]) {
@@ -476,7 +480,7 @@ int udhcpd_main(int argc UNUSED_PARAM, char **argv)
                 case DHCPDISCOVER:
                         log1("Received DISCOVER");
 
-                        send_offer(&packet, static_lease_nip, lease);
+                        send_offer(&packet, static_lease_nip, lease, requested_ip_opt);
                         break;
 
                 case DHCPREQUEST:
@@ -567,7 +571,7 @@ o DHCPREQUEST generated during REBINDING state:
    A DHCP server MAY extend a client's lease only if it has local
    administrative authority to do so.
 */
-                        if (!requested_opt) {
+                        if (!requested_ip_opt) {
                                 requested_nip = packet.ciaddr;
                                 if (requested_nip == 0) {
                                         log1("no requested IP and no ciaddr, ignoring");
@@ -603,7 +607,7 @@ o DHCPREQUEST generated during REBINDING state:
                          */
                         log1("Received DECLINE");
                         if (server_id_opt
-                         && requested_opt
+                         && requested_ip_opt
                          && lease  /* chaddr matches this lease */
                          && requested_nip == lease->lease_nip
                         ) {