usr.sbin/rdate/rdate.c

   1 /*      $NetBSD: rdate.c,v 1.19 2009/10/21 01:07:47 snj Exp $   */
   2
   3 /*
   4  * Copyright (c) 1994 Christos Zoulas
   5  * All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  *
  16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  17  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  18  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  19  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  21  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  22  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  23  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  24  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  25  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  26  */
  27
  28 /*
  29  * rdate.c: Set the date from the specified host
  30  *
  31  *      Uses the rfc868 time protocol at socket 37.
  32  *      Time is returned as the number of seconds since
  33  *      midnight January 1st 1900.
  34  */
  35 #include <sys/cdefs.h>
  36 #ifndef lint
  37 __RCSID("$NetBSD: rdate.c,v 1.19 2009/10/21 01:07:47 snj Exp $");
  38 #endif /* lint */
  39
  40 #include <sys/types.h>
  41 #include <sys/socket.h>
  42 #include <sys/time.h>
  43
  44 #include <netinet/in.h>
  45
  46 #include <err.h>
  47 #include <netdb.h>
  48 #include <stdio.h>
  49 #include <stdlib.h>
  50 #include <string.h>
  51 #include <unistd.h>
  52 #include <util.h>
  53
  54 /* seconds from midnight Jan 1900 - 1970 */
  55 #define DIFFERENCE 2208988800ULL
  56
  57         int     main(int, char **);
  58 static  void    usage(void);
  59
  60 static void
  61 usage(void)
  62 {
  63         (void) fprintf(stderr, "usage: %s [-psa] host\n", getprogname());
  64         (void) fprintf(stderr, "  -p: just print, don't set\n");
  65         (void) fprintf(stderr, "  -s: just set, don't print\n");
  66         (void) fprintf(stderr, "  -a: use adjtime instead of instant change\n");
  67 }
  68
  69 int
  70 main(int argc, char *argv[])
  71 {
  72         int             pr = 0, silent = 0, s;
  73         int             slidetime = 0;
  74         int             adjustment;
  75         uint32_t        data;
  76         time_t          tim;
  77         char           *hname;
  78         const char     *emsg = NULL;
  79         struct addrinfo hints, *res, *res0;
  80         int             c;
  81         int             error;
  82
  83         adjustment = 0;
  84         while ((c = getopt(argc, argv, "psa")) != -1)
  85                 switch (c) {
  86                 case 'p':
  87                         pr++;
  88                         break;
  89
  90                 case 's':
  91                         silent++;
  92                         break;
  93
  94                 case 'a':
  95                         slidetime++;
  96                         break;
  97
  98                 default:
  99                         usage();
 100                         return 1;
 101                 }
 102
 103         if (argc - 1 != optind) {
 104                 usage();
 105                 return 1;
 106         }
 107         hname = argv[optind];
 108
 109         memset(&hints, 0, sizeof (hints));
 110         hints.ai_family = PF_UNSPEC;
 111         hints.ai_socktype = SOCK_STREAM;
 112         hints.ai_flags = AI_CANONNAME;
 113         error = getaddrinfo(hname, "time", &hints, &res0);
 114         if (error)
 115                 errx(1, "%s: %s", gai_strerror(error), hname);
 116
 117         for (res = res0, s = -1; res != NULL; res = res->ai_next) {
 118                 s = socket(res->ai_family, res->ai_socktype, res->ai_protocol);
 119                 if (s < 0) {
 120                         emsg = "socket";
 121                         continue;
 122                 }
 123
 124                 if (connect(s, res->ai_addr, res->ai_addrlen)) {
 125                         close(s);
 126                         s = -1;
 127                         emsg = "connect";
 128                         continue;
 129                 }
 130
 131                 break;
 132         }
 133         if (s < 0)
 134                 err(1, "%s", emsg);
 135
 136         if (read(s, &data, sizeof(uint32_t)) != sizeof(uint32_t))
 137                 err(1, "Could not read data");
 138
 139         (void) close(s);
 140         tim = ntohl(data) - DIFFERENCE;
 141
 142         if (!pr) {
 143             struct timeval  tv;
 144             if (!slidetime) {
 145                     logwtmp("|", "date", "");
 146                     tv.tv_sec = tim;
 147                     tv.tv_usec = 0;
 148                     if (settimeofday(&tv, NULL) == -1)
 149                             err(1, "Could not set time of day");
 150                     logwtmp("{", "date", "");
 151             } else {
 152                     struct timeval tv_current;
 153                     if (gettimeofday(&tv_current, NULL) == -1)
 154                             err(1, "Could not get local time of day");
 155                     adjustment = tv.tv_sec = tim - tv_current.tv_sec;
 156                     tv.tv_usec = 0;
 157                     if (adjtime(&tv, NULL) == -1)
 158                             err(1, "Could not adjust time of day");
 159             }
 160         }
 161
 162         if (!silent) {
 163                 (void) fputs(ctime(&tim), stdout);
 164                 if (slidetime)
 165                     (void) fprintf(stdout,
 166                                    "%s: adjust local clock by %d seconds\n",
 167                                    getprogname(), adjustment);
 168         }
 169         return 0;
 170 }