1 /* $NetBSD: rdate.c,v 1.4 1996/03/16 12:37:45 pk 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 * 3. All advertising materials mentioning features or use of this software 16 * must display the following acknowledgement: 17 * This product includes software developed by Christos Zoulas. 18 * 4. The name of the author may not be used to endorse or promote products 19 * derived from this software without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 22 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 23 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 24 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 25 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 26 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 27 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 28 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 29 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 30 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 31 */ 32 33 /* 34 * rdate.c: Set the date from the specified host 35 * 36 * Uses the rfc868 time protocol at socket 37. 37 * Time is returned as the number of seconds since 38 * midnight January 1st 1900. 39 */ 40 #ifndef lint 41 static char rcsid[] = "$NetBSD: rdate.c,v 1.4 1996/03/16 12:37:45 pk Exp $"; 42 #endif/* lint */ 43 44 #include <sys/types.h> 45 #include <sys/param.h> 46 #include <stdio.h> 47 #include <ctype.h> 48 #include <string.h> 49 #include <sys/time.h> 50 #include <sys/socket.h> 51 #include <netdb.h> 52 #include <netinet/in.h> 53 54 /* seconds from midnight Jan 1900 - 1970 */ 55 #if __STDC__ 56 #define DIFFERENCE 2208988800UL 57 #else 58 #define DIFFERENCE 2208988800 59 #endif 60 61 extern char *__progname; 62 63 static void 64 usage() 65 { 66 (void) fprintf(stderr, "Usage: %s [-psa] host\n", __progname); 67 (void) fprintf(stderr, " -p: just print, don't set\n"); 68 (void) fprintf(stderr, " -s: just set, don't print\n"); 69 (void) fprintf(stderr, " -a: use adjtime instead of instant change\n"); 70 } 71 72 int 73 main(argc, argv) 74 int argc; 75 char *argv[]; 76 { 77 int pr = 0, silent = 0, s; 78 int slidetime = 0; 79 int adjustment; 80 time_t tim; 81 char *hname; 82 struct hostent *hp; 83 struct protoent *pp, ppp; 84 struct servent *sp, ssp; 85 struct sockaddr_in sa; 86 extern int optind; 87 int c; 88 89 while ((c = getopt(argc, argv, "psa")) != -1) 90 switch (c) { 91 case 'p': 92 pr++; 93 break; 94 95 case 's': 96 silent++; 97 break; 98 99 case 'a': 100 slidetime++; 101 break; 102 103 default: 104 usage(); 105 return 1; 106 } 107 108 if (argc - 1 != optind) { 109 usage(); 110 return 1; 111 } 112 hname = argv[optind]; 113 114 if ((hp = gethostbyname(hname)) == NULL) { 115 (void) fprintf(stderr, "%s: ", __progname); 116 herror(hname); 117 return 1; 118 } 119 120 if ((sp = getservbyname("time", "tcp")) == NULL) { 121 sp = &ssp; 122 sp->s_port = 37; 123 sp->s_proto = "tcp"; 124 } 125 if ((pp = getprotobyname(sp->s_proto)) == NULL) { 126 pp = &ppp; 127 pp->p_proto = 6; 128 } 129 if ((s = socket(AF_INET, SOCK_STREAM, pp->p_proto)) == -1) 130 err(1, "Could not create socket"); 131 132 bzero(&sa, sizeof sa); 133 sa.sin_family = AF_INET; 134 sa.sin_port = sp->s_port; 135 136 memcpy(&(sa.sin_addr.s_addr), hp->h_addr, hp->h_length); 137 138 if (connect(s, (struct sockaddr *) & sa, sizeof(sa)) == -1) 139 err(1, "Could not connect socket"); 140 141 if (read(s, &tim, sizeof(time_t)) != sizeof(time_t)) 142 err(1, "Could not read data"); 143 144 (void) close(s); 145 tim = ntohl(tim) - DIFFERENCE; 146 147 if (!pr) { 148 struct timeval tv; 149 if (!slidetime) { 150 tv.tv_sec = tim; 151 tv.tv_usec = 0; 152 if (settimeofday(&tv, NULL) == -1) 153 err(1, "Could not set time of day"); 154 } else { 155 struct timeval tv_current; 156 if (gettimeofday(&tv_current, NULL) == -1) 157 err(1, "Could not get local time of day"); 158 adjustment = tv.tv_sec = tim - tv_current.tv_sec; 159 tv.tv_usec = 0; 160 if (adjtime(&tv, NULL) == -1) 161 err(1, "Could not adjust time of day"); 162 } 163 } 164 165 if (!silent) { 166 (void) fputs(ctime(&tim), stdout); 167 if (slidetime) 168 (void) fprintf(stdout, 169 "%s: adjust local clock by %d seconds\n", 170 __progname, adjustment); 171 } 172 return 0; 173 } 174