If a lease is negotiated, then expires after renewal attempts, don't time out

and exit the daemon as would be desirable at startup.  Just keep trying.

ndhc/arp.c

@@ -218,6 +218,7 @@ void arp_success(struct client_state_t *cs)
              inet_ntoa(temp_addr), cs->lease);
     cs->requestedIP = arp_dhcp_packet.yiaddr;
     cs->dhcpState = DS_BOUND;
+    cs->init = 0;
     ifchange(&arp_dhcp_packet,
              ((cs->arpPrevState == DS_RENEWING ||
                cs->arpPrevState == DS_REBINDING)

ndhc/config.h

@@ -65,6 +65,7 @@ struct client_state_t {
     uint32_t requestedIP, serverAddr, routerAddr;
     uint32_t lease, t1, t2, xid;
     uint8_t routerArp[6];
+    uint8_t init;
 };
 
 struct client_config_t {

ndhc/ndhc.c

@@ -67,6 +67,7 @@ struct client_state_t cs = {
     .packetNum = 0,
     .xid = 0,
     .timeout = 0,
+    .init = 1,
     .oldTimeout = 0,
     .leaseStartTime = 0,
     .requestedIP = 0,

ndhc/timeout.c

@@ -39,6 +39,7 @@ static void init_selecting_timeout(struct client_state_t *cs)
         cs->timeout = DELAY_SEC * (cs->packetNum + 1) * 1000;
         cs->packetNum++;
     } else {
+        if (cs->init) {
             if (client_config.background_if_no_lease) {
                 log_line("No lease, going to background.");
                 background(cs);
@@ -46,6 +47,7 @@ static void init_selecting_timeout(struct client_state_t *cs)
                 log_line("No lease, failing.");
                 exit(EXIT_FAILURE);
             }
+        }
         /* wait to try again */
         cs->packetNum = 0;
         cs->timeout = RETRY_DELAY * 1000;