source: MondoRescue/branches/3.2/mindi-busybox/networking/udhcp/dumpleases.c

/* vi: set sw=4 ts=4: */
/*
 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
 */

//usage:#define dumpleases_trivial_usage
//usage:       "[-r|-a] [-f LEASEFILE]"
//usage:#define dumpleases_full_usage "\n\n"
//usage:       "Display DHCP leases granted by udhcpd\n"
//usage:    IF_LONG_OPTS(
//usage:     "\n    -f,--file=FILE  Lease file"
//usage:     "\n    -r,--remaining  Show remaining time"
//usage:     "\n    -a,--absolute   Show expiration time"
//usage:    )
//usage:    IF_NOT_LONG_OPTS(
//usage:     "\n    -f FILE Lease file"
//usage:     "\n    -r  Show remaining time"
//usage:     "\n    -a  Show expiration time"
//usage:    )

#include "common.h"
#include "dhcpd.h"
#include "unicode.h"

int dumpleases_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int dumpleases_main(int argc UNUSED_PARAM, char **argv)
{
    int fd;
    int i;
    unsigned opt;
    int64_t written_at, curr, expires_abs;
    const char *file = LEASES_FILE;
    struct dyn_lease lease;
    struct in_addr addr;

    enum {
        OPT_a = 0x1, // -a
        OPT_r = 0x2, // -r
        OPT_f = 0x4, // -f
    };
#if ENABLE_LONG_OPTS
    static const char dumpleases_longopts[] ALIGN1 =
        "absolute\0"  No_argument       "a"
        "remaining\0" No_argument       "r"
        "file\0"      Required_argument "f"
        ;

    applet_long_options = dumpleases_longopts;
#endif
    init_unicode();

    opt_complementary = "=0:a--r:r--a";
    opt = getopt32(argv, "arf:", &file);

    fd = xopen(file, O_RDONLY);

    printf("Mac Address       IP Address      Host Name           Expires %s\n", (opt & OPT_a) ? "at" : "in");
    /*     "00:00:00:00:00:00 255.255.255.255 ABCDEFGHIJKLMNOPQRS Wed Jun 30 21:49:08 1993" */
    /*     "123456789 123456789 123456789 123456789 123456789 123456789 123456789 123456789 */

    xread(fd, &written_at, sizeof(written_at));
    written_at = SWAP_BE64(written_at);
    curr = time(NULL);
    if (curr < written_at)
        written_at = curr; /* lease file from future! :) */

    while (full_read(fd, &lease, sizeof(lease)) == sizeof(lease)) {
        const char *fmt = ":%02x" + 1;
        for (i = 0; i < 6; i++) {
            printf(fmt, lease.lease_mac[i]);
            fmt = ":%02x";
        }
        addr.s_addr = lease.lease_nip;
#if ENABLE_UNICODE_SUPPORT
        {
            char *uni_name = unicode_conv_to_printable_fixedwidth(/*NULL,*/ lease.hostname, 19);
            printf(" %-16s%s ", inet_ntoa(addr), uni_name);
            free(uni_name);
        }
#else
        /* actually, 15+1 and 19+1, +1 is a space between columns */
        /* lease.hostname is char[20] and is always NUL terminated */
        printf(" %-16s%-20s", inet_ntoa(addr), lease.hostname);
#endif
        expires_abs = ntohl(lease.expires) + written_at;
        if (expires_abs <= curr) {
            puts("expired");
            continue;
        }
        if (!(opt & OPT_a)) { /* no -a */
            unsigned d, h, m;
            unsigned expires = expires_abs - curr;
            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_abs;
            fputs(ctime(&t), stdout);
        }
    }
    /* close(fd); */

    return 0;
}