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
   6 //usage:#define dumpleases_trivial_usage
   7 //usage:       "[-r|-a] [-f LEASEFILE]"
   8 //usage:#define dumpleases_full_usage "\n\n"
   9 //usage:       "Display DHCP leases granted by udhcpd\n"
  10 //usage:     "\nOptions:"
  11 //usage:        IF_LONG_OPTS(
  12 //usage:     "\n        -f,--file=FILE  Lease file"
  13 //usage:     "\n        -r,--remaining  Show remaining time"
  14 //usage:     "\n        -a,--absolute   Show expiration time"
  15 //usage:        )
  16 //usage:        IF_NOT_LONG_OPTS(
  17 //usage:     "\n        -f FILE Lease file"
  18 //usage:     "\n        -r      Show remaining time"
  19 //usage:     "\n        -a      Show expiration time"
  20 //usage:        )
  21
  22 #include "common.h"
  23 #include "dhcpd.h"
  24 #include "unicode.h"
  25
  26 int dumpleases_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
  27 int dumpleases_main(int argc UNUSED_PARAM, char **argv)
  28 {
  29         int fd;
  30         int i;
  31         unsigned opt;
  32         int64_t written_at, curr, expires_abs;
  33         const char *file = LEASES_FILE;
  34         struct dyn_lease lease;
  35         struct in_addr addr;
  36
  37         enum {
  38                 OPT_a = 0x1, // -a
  39                 OPT_r = 0x2, // -r
  40                 OPT_f = 0x4, // -f
  41         };
  42 #if ENABLE_LONG_OPTS
  43         static const char dumpleases_longopts[] ALIGN1 =
  44                 "absolute\0"  No_argument       "a"
  45                 "remaining\0" No_argument       "r"
  46                 "file\0"      Required_argument "f"
  47                 ;
  48
  49         applet_long_options = dumpleases_longopts;
  50 #endif
  51         init_unicode();
  52
  53         opt_complementary = "=0:a--r:r--a";
  54         opt = getopt32(argv, "arf:", &file);
  55
  56         fd = xopen(file, O_RDONLY);
  57
  58         printf("Mac Address       IP Address      Host Name           Expires %s\n", (opt & OPT_a) ? "at" : "in");
  59         /*     "00:00:00:00:00:00 255.255.255.255 ABCDEFGHIJKLMNOPQRS Wed Jun 30 21:49:08 1993" */
  60         /*     "123456789 123456789 123456789 123456789 123456789 123456789 123456789 123456789 */
  61
  62         xread(fd, &written_at, sizeof(written_at));
  63         written_at = SWAP_BE64(written_at);
  64         curr = time(NULL);
  65         if (curr < written_at)
  66                 written_at = curr; /* lease file from future! :) */
  67
  68         while (full_read(fd, &lease, sizeof(lease)) == sizeof(lease)) {
  69                 const char *fmt = ":%02x" + 1;
  70                 for (i = 0; i < 6; i++) {
  71                         printf(fmt, lease.lease_mac[i]);
  72                         fmt = ":%02x";
  73                 }
  74                 addr.s_addr = lease.lease_nip;
  75 #if ENABLE_UNICODE_SUPPORT
  76                 {
  77                         char *uni_name = unicode_conv_to_printable_fixedwidth(/*NULL,*/ lease.hostname, 19);
  78                         printf(" %-16s%s ", inet_ntoa(addr), uni_name);
  79                         free(uni_name);
  80                 }
  81 #else
  82                 /* actually, 15+1 and 19+1, +1 is a space between columns */
  83                 /* lease.hostname is char[20] and is always NUL terminated */
  84                 printf(" %-16s%-20s", inet_ntoa(addr), lease.hostname);
  85 #endif
  86                 expires_abs = ntohl(lease.expires) + written_at;
  87                 if (expires_abs <= curr) {
  88                         puts("expired");
  89                         continue;
  90                 }
  91                 if (!(opt & OPT_a)) { /* no -a */
  92                         unsigned d, h, m;
  93                         unsigned expires = expires_abs - curr;
  94                         d = expires / (24*60*60); expires %= (24*60*60);
  95                         h = expires / (60*60); expires %= (60*60);
  96                         m = expires / 60; expires %= 60;
  97                         if (d)
  98                                 printf("%u days ", d);
  99                         printf("%02u:%02u:%02u\n", h, m, (unsigned)expires);
 100                 } else { /* -a */
 101                         time_t t = expires_abs;
 102                         fputs(ctime(&t), stdout);
 103                 }
 104         }
 105         /* close(fd); */
 106
 107         return 0;
 108 }