udhcpd: disable opton to have absolute lease times in lease file

 (that does not work with dumpleases)
dumpleases: fix -a option.
networking/udhcp/*: code shrink, more compact static leases struture,
 better comments, etc

function                                             old     new   delta
find_free_or_expired_address                           -     147    +147
nobody_responds_to_arp                                 -      84     +84
read_opt                                             781     830     +49
dumpleases_main                                      435     447     +12
send_ACK                                             229     232      +3
read_staticlease                                      90      93      +3
addStaticLease                                        60      61      +1
getIpByMac                                            46      43      -3
reservedIp                                            31      20     -11
keywords                                             304     288     -16
send_offer                                           428     403     -25
write_leases                                         225     193     -32
read_leases                                          184     143     -41
read_yn                                               64       -     -64
find_address                                         191       -    -191
------------------------------------------------------------------------------
(add/remove: 2/2 grow/shrink: 5/6 up/down: 299/-383)          Total: -84 bytes

1 files changed, 23 insertions, 16 deletions

diff --git a/networking/udhcp/dumpleases.c b/networking/udhcp/dumpleases.c
index 3e193903d..2d16ec160 100644
--- a/networking/udhcp/dumpleases.c
+++ b/networking/udhcp/dumpleases.c
@@ -12,7 +12,8 @@ int dumpleases_main(int argc UNUSED_PARAM, char **argv)
         int fd;
         int i;
         unsigned opt;
-        time_t expires;
+        leasetime_t expires;
+        leasetime_t curr;
         const char *file = LEASES_FILE;
         struct dhcpOfferedAddr lease;
         struct in_addr addr;
@@ -38,27 +39,33 @@ int dumpleases_main(int argc UNUSED_PARAM, char **argv)
 
         printf("Mac Address       IP-Address      Expires %s\n", (opt & OPT_a) ? "at" : "in");
         /*     "00:00:00:00:00:00 255.255.255.255 Wed Jun 30 21:49:08 1993" */
+
+        curr = time(NULL);
         while (full_read(fd, &lease, sizeof(lease)) == sizeof(lease)) {
-                printf(":%02x"+1, lease.chaddr[0]);
-                for (i = 1; i < 6; i++) {
-                        printf(":%02x", lease.chaddr[i]);
+                const char *fmt = ":%02x" + 1;
+                for (i = 0; i < 6; i++) {
+                        printf(fmt, lease.chaddr[i]);
+                        fmt = ":%02x";
                 }
                 addr.s_addr = lease.yiaddr;
                 printf(" %-15s ", inet_ntoa(addr));
+                if (lease.expires == 0) {
+                        puts("expired");
+                        continue;
+                }
                 expires = ntohl(lease.expires);
                 if (!(opt & OPT_a)) { /* no -a */
-                        if (!expires)
-                                puts("expired");
-                        else {
-                                unsigned d, h, m;
-                                d = expires / (24*60*60); expires %= (24*60*60);
-                                h = expires / (60*60); expires %= (60*60);
-                                m = expires / 60; expires %= 60;
-                                if (d) printf("%u days ", d);
-                                printf("%02u:%02u:%02u\n", h, m, (unsigned)expires);
-                        }
-                } else /* -a */
-                        fputs(ctime(&expires), stdout);
+                        unsigned d, h, m;
+                        d = expires / (24*60*60); expires %= (24*60*60);
+                        h = expires / (60*60); expires %= (60*60);
+                        m = expires / 60; expires %= 60;
+                        if (d)
+                                printf("%u days ", d);
+                        printf("%02u:%02u:%02u\n", h, m, (unsigned)expires);
+                } else { /* -a */
+                        time_t t = expires + curr;
+                        fputs(ctime(&t), stdout);
+                }
         }
         /* close(fd); */