LXR busybox/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//applet:IF_DUMPLEASES(APPLET_NOEXEC(dumpleases, dumpleases, BB_DIR_USR_BIN, BB_SUID_DROP, dumpleases))
   6
   7//kbuild:lib-$(CONFIG_DUMPLEASES) += dumpleases.o
   8
   9//usage:#define dumpleases_trivial_usage
  10//usage:       "[-r|-a] [-d] [-f LEASEFILE]"
  11//usage:#define dumpleases_full_usage "\n\n"
  12//usage:       "Display DHCP leases granted by udhcpd\n"
  13//usage:     "\n        -f FILE Lease file"
  14//usage:     "\n        -r      Show remaining time"
  15//usage:     "\n        -a      Show expiration time"
  16//usage:     "\n        -d      Show time in seconds"
  17
  18#include "common.h"
  19#include "dhcpd.h"
  20#include "unicode.h"
  21
  22int dumpleases_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
  23int dumpleases_main(int argc UNUSED_PARAM, char **argv)
  24{
  25        int fd;
  26        int i;
  27        unsigned opt;
  28        int64_t written_at, curr;
  29        const char *file = LEASES_FILE;
  30        struct dyn_lease lease;
  31
  32        enum {
  33                OPT_a = 0x1, // -a
  34                OPT_r = 0x2, // -r
  35                OPT_f = 0x4, // -f
  36                OPT_d = 0x8, // -d
  37        };
  38#if ENABLE_LONG_OPTS
  39        static const char dumpleases_longopts[] ALIGN1 =
  40                "absolute\0"  No_argument       "a"
  41                "remaining\0" No_argument       "r"
  42                "file\0"      Required_argument "f"
  43                "decimal\0"   No_argument       "d"
  44                ;
  45
  46#endif
  47        init_unicode();
  48
  49        opt = getopt32long(argv, "^"
  50                        "arf:d"
  51                        "\0" "=0:a--r:r--a",
  52                        dumpleases_longopts,
  53                        &file
  54        );
  55
  56        fd = xopen(file, O_RDONLY);
  57
  58        /*     "123456789 123456789 123456789 123456789 123456789 123456789 123456789 123456789 */
  59        /*     "00:00:00:00:00:00 255.255.255.255 ABCDEFGHIJKLMNOPQRS Wed Jun 30 21:49:08 1993" */
  60        printf("Mac %-14s"       "IP %-13s"      "Host %-15s"        "Expires %s\n",
  61                "Address", "Address", "Name",
  62                (opt & OPT_a) ? "at" : "in"
  63        );
  64
  65        xread(fd, &written_at, sizeof(written_at));
  66        written_at = SWAP_BE64(written_at);
  67        curr = time(NULL);
  68        if (curr < written_at)
  69                written_at = curr; /* lease file from future! :) */
  70
  71        while (full_read(fd, &lease, sizeof(lease)) == sizeof(lease)) {
  72                struct in_addr addr;
  73                int64_t expires_abs;
  74
  75                const char *fmt = ":%02x" + 1;
  76                for (i = 0; i < 6; i++) {
  77                        printf(fmt, lease.lease_mac[i]);
  78                        fmt = ":%02x";
  79                }
  80                addr.s_addr = lease.lease_nip;
  81#if ENABLE_UNICODE_SUPPORT
  82                {
  83                        char *uni_name = unicode_conv_to_printable_fixedwidth(/*NULL,*/ lease.hostname, 19);
  84                        printf(" %-16s%s ", inet_ntoa(addr), uni_name);
  85                        free(uni_name);
  86                }
  87#else
  88                /* actually, 15+1 and 19+1, +1 is a space between columns */
  89                /* lease.hostname is char[20] and is always NUL terminated */
  90                printf(" %-16s%-20s", inet_ntoa(addr), lease.hostname);
  91#endif
  92                expires_abs = ntohl(lease.expires) + written_at;
  93                if (expires_abs <= curr) {
  94                        puts("expired");
  95                        continue;
  96                }
  97                if (opt & OPT_d) {
  98                        /* -d: decimal time */
  99                        if (!(opt & OPT_a))
 100                                expires_abs -= curr;
 101                        printf("%llu\n", (unsigned long long) expires_abs);
 102                        continue;
 103                }
 104                if (!(opt & OPT_a)) { /* no -a */
 105                        unsigned d, h, m;
 106                        unsigned expires = expires_abs - curr;
 107                        d = expires / (24*60*60); expires %= (24*60*60);
 108                        h = expires / (60*60); expires %= (60*60);
 109                        m = expires / 60; expires %= 60;
 110                        if (d)
 111                                printf("%u days ", d);
 112                        printf("%02u:%02u:%02u\n", h, m, (unsigned)expires);
 113                } else { /* -a */
 114                        time_t t = expires_abs;
 115                        fputs_stdout(ctime(&t));
 116                }
 117        }
 118        /* close(fd); */
 119
 120        return 0;
 121}
 122