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:        IF_LONG_OPTS(
  14//usage:     "\n        -f,--file FILE  Lease file"
  15//usage:     "\n        -r,--remaining  Show remaining time"
  16//usage:     "\n        -a,--absolute   Show expiration time"
  17//usage:     "\n        -d,--decimal    Show time in seconds"
  18//usage:        )
  19//usage:        IF_NOT_LONG_OPTS(
  20//usage:     "\n        -f FILE Lease file"
  21//usage:     "\n        -r      Show remaining time"
  22//usage:     "\n        -a      Show expiration time"
  23//usage:     "\n        -d      Show time in seconds"
  24//usage:        )
  25
  26#include "common.h"
  27#include "dhcpd.h"
  28#include "unicode.h"
  29
  30int dumpleases_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
  31int dumpleases_main(int argc UNUSED_PARAM, char **argv)
  32{
  33        int fd;
  34        int i;
  35        unsigned opt;
  36        int64_t written_at, curr;
  37        const char *file = LEASES_FILE;
  38        struct dyn_lease lease;
  39
  40        enum {
  41                OPT_a = 0x1, // -a
  42                OPT_r = 0x2, // -r
  43                OPT_f = 0x4, // -f
  44                OPT_d = 0x8, // -d
  45        };
  46#if ENABLE_LONG_OPTS
  47        static const char dumpleases_longopts[] ALIGN1 =
  48                "absolute\0"  No_argument       "a"
  49                "remaining\0" No_argument       "r"
  50                "file\0"      Required_argument "f"
  51                "decimal\0"   No_argument       "d"
  52                ;
  53
  54#endif
  55        init_unicode();
  56
  57        opt = getopt32long(argv, "^"
  58                        "arf:d"
  59                        "\0" "=0:a--r:r--a",
  60                        dumpleases_longopts,
  61                        &file
  62        );
  63
  64        fd = xopen(file, O_RDONLY);
  65
  66        /*     "123456789 123456789 123456789 123456789 123456789 123456789 123456789 123456789 */
  67        /*     "00:00:00:00:00:00 255.255.255.255 ABCDEFGHIJKLMNOPQRS Wed Jun 30 21:49:08 1993" */
  68        printf("Mac %-14s"       "IP %-13s"      "Host %-15s"        "Expires %s\n",
  69                "Address", "Address", "Name",
  70                (opt & OPT_a) ? "at" : "in"
  71        );
  72
  73        xread(fd, &written_at, sizeof(written_at));
  74        written_at = SWAP_BE64(written_at);
  75        curr = time(NULL);
  76        if (curr < written_at)
  77                written_at = curr; /* lease file from future! :) */
  78
  79        while (full_read(fd, &lease, sizeof(lease)) == sizeof(lease)) {
  80                struct in_addr addr;
  81                int64_t expires_abs;
  82
  83                const char *fmt = ":%02x" + 1;
  84                for (i = 0; i < 6; i++) {
  85                        printf(fmt, lease.lease_mac[i]);
  86                        fmt = ":%02x";
  87                }
  88                addr.s_addr = lease.lease_nip;
  89#if ENABLE_UNICODE_SUPPORT
  90                {
  91                        char *uni_name = unicode_conv_to_printable_fixedwidth(/*NULL,*/ lease.hostname, 19);
  92                        printf(" %-16s%s ", inet_ntoa(addr), uni_name);
  93                        free(uni_name);
  94                }
  95#else
  96                /* actually, 15+1 and 19+1, +1 is a space between columns */
  97                /* lease.hostname is char[20] and is always NUL terminated */
  98                printf(" %-16s%-20s", inet_ntoa(addr), lease.hostname);
  99#endif
 100                expires_abs = ntohl(lease.expires) + written_at;
 101                if (expires_abs <= curr) {
 102                        puts("expired");
 103                        continue;
 104                }
 105                if (opt & OPT_d) {
 106                        /* -d: decimal time */
 107                        if (!(opt & OPT_a))
 108                                expires_abs -= curr;
 109                        printf("%llu\n", (unsigned long long) expires_abs);
 110                        continue;
 111                }
 112                if (!(opt & OPT_a)) { /* no -a */
 113                        unsigned d, h, m;
 114                        unsigned expires = expires_abs - curr;
 115                        d = expires / (24*60*60); expires %= (24*60*60);
 116                        h = expires / (60*60); expires %= (60*60);
 117                        m = expires / 60; expires %= 60;
 118                        if (d)
 119                                printf("%u days ", d);
 120                        printf("%02u:%02u:%02u\n", h, m, (unsigned)expires);
 121                } else { /* -a */
 122                        time_t t = expires_abs;
 123                        fputs(ctime(&t), stdout);
 124                }
 125        }
 126        /* close(fd); */
 127
 128        return 0;
 129}
 130