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      1 /*	$NetBSD: rdate.c,v 1.22 2017/08/26 19:26:32 ginsbach 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 1.22 2017/08/26 19:26:32 ginsbach 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 static	void	usage(void);
     58 
     59 static void
     60 usage(void)
     61 {
     62 	(void) fprintf(stderr, "usage: %s [-46aps] host\n", getprogname());
     63 	(void) fprintf(stderr, "  -4: use IPv4 addresses only\n");
     64 	(void) fprintf(stderr, "  -6: use IPv6 addresses only\n");
     65 	(void) fprintf(stderr, "  -a: use adjtime instead of instant change\n");
     66 	(void) fprintf(stderr, "  -p: just print, don't set\n");
     67 	(void) fprintf(stderr, "  -s: just set, don't print\n");
     68 }
     69 
     70 int
     71 main(int argc, char *argv[])
     72 {
     73 	int             pr = 0, silent = 0, s;
     74 	int		slidetime = 0;
     75 	int		adjustment;
     76 	uint32_t	data;
     77 	time_t          tim;
     78 	char           *hname;
     79 	const char     *emsg = NULL;
     80 	struct addrinfo	hints, *res, *res0;
     81 	int             c;
     82 	int		error;
     83 	int		family = AF_UNSPEC;
     84 
     85 	adjustment = 0;
     86 	while ((c = getopt(argc, argv, "46aps")) != -1)
     87 		switch (c) {
     88 		case '4':
     89 			family = AF_INET;
     90 			break;
     91 
     92 		case '6':
     93 			family  = AF_INET6;
     94 			break;
     95 
     96 		case 'a':
     97 			slidetime++;
     98 			break;
     99 
    100 		case 'p':
    101 			pr++;
    102 			break;
    103 
    104 		case 's':
    105 			silent++;
    106 			break;
    107 
    108 		default:
    109 			usage();
    110 			return 1;
    111 		}
    112 
    113 	if (argc - 1 != optind) {
    114 		usage();
    115 		return 1;
    116 	}
    117 	hname = argv[optind];
    118 
    119 	memset(&hints, 0, sizeof (hints));
    120 	hints.ai_family = family;
    121 	hints.ai_socktype = SOCK_STREAM;
    122 	hints.ai_flags = AI_CANONNAME;
    123 	error = getaddrinfo(hname, "time", &hints, &res0);
    124 	if (error)
    125 		errx(1, "%s: %s", gai_strerror(error), hname);
    126 
    127 	for (res = res0, s = -1; res != NULL; res = res->ai_next) {
    128 		s = socket(res->ai_family, res->ai_socktype, res->ai_protocol);
    129 		if (s < 0) {
    130 			emsg = "socket";
    131 			continue;
    132 		}
    133 
    134 		if (connect(s, res->ai_addr, res->ai_addrlen)) {
    135 			close(s);
    136 			s = -1;
    137 			emsg = "connect";
    138 			continue;
    139 		}
    140 
    141 		break;
    142 	}
    143 	if (s < 0)
    144 		err(1, "%s", emsg);
    145 
    146 	if (read(s, &data, sizeof(uint32_t)) != sizeof(uint32_t))
    147 		err(1, "Could not read data");
    148 
    149 	(void) close(s);
    150 	tim = ntohl(data) - DIFFERENCE;
    151 
    152 	if (!pr) {
    153 	    struct timeval  tv;
    154 	    if (!slidetime) {
    155 		    logwtmp("|", "date", "");
    156 		    tv.tv_sec = tim;
    157 		    tv.tv_usec = 0;
    158 		    if (settimeofday(&tv, NULL) == -1)
    159 			    err(1, "Could not set time of day");
    160 		    logwtmp("{", "date", "");
    161 	    } else {
    162 		    struct timeval tv_current;
    163 		    if (gettimeofday(&tv_current, NULL) == -1)
    164 			    err(1, "Could not get local time of day");
    165 		    adjustment = tv.tv_sec = tim - tv_current.tv_sec;
    166 		    tv.tv_usec = 0;
    167 		    if (adjtime(&tv, NULL) == -1)
    168 			    err(1, "Could not adjust time of day");
    169 	    }
    170 	}
    171 
    172 	if (!silent) {
    173 		(void) fputs(ctime(&tim), stdout);
    174 		if (slidetime)
    175 		    (void) fprintf(stdout,
    176 				   "%s: adjust local clock by %d seconds\n",
    177 				   getprogname(), adjustment);
    178 	}
    179 	return 0;
    180 }
    181