networking/udhcp/dumpleases.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * Licensed under GPLv2 or later, see file LICENSE in this source tree.
   4  */
   5 #include "common.h"
   6 #include "dhcpd.h"
   7 #include "unicode.h"
   8
   9 int dumpleases_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
  10 int dumpleases_main(int argc UNUSED_PARAM, char **argv)
  11 {
  12         int fd;
  13         int i;
  14         unsigned opt;
  15         int64_t written_at, curr, expires_abs;
  16         const char *file = LEASES_FILE;
  17         struct dyn_lease lease;
  18         struct in_addr addr;
  19
  20         enum {
  21                 OPT_a = 0x1, // -a
  22                 OPT_r = 0x2, // -r
  23                 OPT_f = 0x4, // -f
  24         };
  25 #if ENABLE_LONG_OPTS
  26         static const char dumpleases_longopts[] ALIGN1 =
  27                 "absolute\0"  No_argument       "a"
  28                 "remaining\0" No_argument       "r"
  29                 "file\0"      Required_argument "f"
  30                 ;
  31
  32         applet_long_options = dumpleases_longopts;
  33 #endif
  34         init_unicode();
  35
  36         opt_complementary = "=0:a--r:r--a";
  37         opt = getopt32(argv, "arf:", &file);
  38
  39         fd = xopen(file, O_RDONLY);
  40
  41         printf("Mac Address       IP Address      Host Name           Expires %s\n", (opt & OPT_a) ? "at" : "in");
  42         /*     "00:00:00:00:00:00 255.255.255.255 ABCDEFGHIJKLMNOPQRS Wed Jun 30 21:49:08 1993" */
  43         /*     "123456789 123456789 123456789 123456789 123456789 123456789 123456789 123456789 */
  44
  45         xread(fd, &written_at, sizeof(written_at));
  46         written_at = SWAP_BE64(written_at);
  47         curr = time(NULL);
  48         if (curr < written_at)
  49                 written_at = curr; /* lease file from future! :) */
  50
  51         while (full_read(fd, &lease, sizeof(lease)) == sizeof(lease)) {
  52                 const char *fmt = ":%02x" + 1;
  53                 for (i = 0; i < 6; i++) {
  54                         printf(fmt, lease.lease_mac[i]);
  55                         fmt = ":%02x";
  56                 }
  57                 addr.s_addr = lease.lease_nip;
  58 #if ENABLE_UNICODE_SUPPORT
  59                 {
  60                         char *uni_name = unicode_conv_to_printable_fixedwidth(NULL, lease.hostname, 19);
  61                         printf(" %-16s%s ", inet_ntoa(addr), uni_name);
  62                         free(uni_name);
  63                 }
  64 #else
  65                 /* actually, 15+1 and 19+1, +1 is a space between columns */
  66                 /* lease.hostname is char[20] and is always NUL terminated */
  67                 printf(" %-16s%-20s", inet_ntoa(addr), lease.hostname);
  68 #endif
  69                 expires_abs = ntohl(lease.expires) + written_at;
  70                 if (expires_abs <= curr) {
  71                         puts("expired");
  72                         continue;
  73                 }
  74                 if (!(opt & OPT_a)) { /* no -a */
  75                         unsigned d, h, m;
  76                         unsigned expires = expires_abs - curr;
  77                         d = expires / (24*60*60); expires %= (24*60*60);
  78                         h = expires / (60*60); expires %= (60*60);
  79                         m = expires / 60; expires %= 60;
  80                         if (d)
  81                                 printf("%u days ", d);
  82                         printf("%02u:%02u:%02u\n", h, m, (unsigned)expires);
  83                 } else { /* -a */
  84                         time_t t = expires_abs;
  85                         fputs(ctime(&t), stdout);
  86                 }
  87         }
  88         /* close(fd); */
  89
  90         return 0;
  91 }