source: trunk/mindi-busybox/util-linux/rdate.c @ 956

Last change on this file since 956 was 821, checked in by bruno, 13 years ago

Addition of busybox 1.2.1 as a mindi-busybox new package
This should avoid delivering binary files in mindi not built there (Fedora and Debian are quite serious about that)

File size: 1.9 KB
Line 
1/* vi: set sw=4 ts=4: */
2/*
3 * The Rdate command will ask a time server for the RFC 868 time
4 *  and optionally set the system time.
5 *
6 * by Sterling Huxley <sterling@europa.com>
7 *
8 * Licensed under GPL v2 or later, see file License for details.
9*/
10
11#include <sys/types.h>
12#include <sys/socket.h>
13#include <netinet/in.h>
14#include <netdb.h>
15#include <stdio.h>
16#include <string.h>
17#include <time.h>
18#include <stdlib.h>
19#include <unistd.h>
20#include <signal.h>
21
22#include "busybox.h"
23
24
25static const int RFC_868_BIAS = 2208988800UL;
26
27static void socket_timeout(int sig)
28{
29    bb_error_msg_and_die("timeout connecting to time server");
30}
31
32static time_t askremotedate(const char *host)
33{
34    unsigned long nett;
35    struct sockaddr_in s_in;
36    int fd;
37
38    bb_lookup_host(&s_in, host);
39    s_in.sin_port = bb_lookup_port("time", "tcp", 37);
40
41    /* Add a timeout for dead or inaccessible servers */
42    alarm(10);
43    signal(SIGALRM, socket_timeout);
44
45    fd = xconnect(&s_in);
46
47    if (safe_read(fd, (void *)&nett, 4) != 4)    /* read time from server */
48        bb_error_msg_and_die("%s did not send the complete time", host);
49    close(fd);
50
51    /* convert from network byte order to local byte order.
52     * RFC 868 time is the number of seconds
53     *  since 00:00 (midnight) 1 January 1900 GMT
54     *  the RFC 868 time 2,208,988,800 corresponds to 00:00  1 Jan 1970 GMT
55     * Subtract the RFC 868 time  to get Linux epoch
56     */
57
58    return(ntohl(nett) - RFC_868_BIAS);
59}
60
61int rdate_main(int argc, char **argv)
62{
63    time_t remote_time;
64    unsigned long flags;
65
66    bb_opt_complementally = "-1";
67    flags = bb_getopt_ulflags(argc, argv, "sp");
68
69    remote_time = askremotedate(argv[optind]);
70
71    if ((flags & 2) == 0) {
72        time_t current_time;
73
74        time(&current_time);
75        if (current_time == remote_time)
76            bb_error_msg("Current time matches remote time.");
77        else
78            if (stime(&remote_time) < 0)
79                bb_perror_msg_and_die("Could not set time of day");
80    }
81
82    if ((flags & 1) == 0)
83        printf("%s", ctime(&remote_time));
84
85    return EXIT_SUCCESS;
86}
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