usr/src/ucblib/librpcsoc/rtime.c

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License, Version 1.0 only
   6  * (the "License").  You may not use this file except in compliance
   7  * with the License.
   8  *
   9  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
  10  * or http://www.opensolaris.org/os/licensing.
  11  * See the License for the specific language governing permissions
  12  * and limitations under the License.
  13  *
  14  * When distributing Covered Code, include this CDDL HEADER in each
  15  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  16  * If applicable, add the following below this CDDL HEADER, with the
  17  * fields enclosed by brackets "[]" replaced with your own identifying
  18  * information: Portions Copyright [yyyy] [name of copyright owner]
  19  *
  20  * CDDL HEADER END
  21  */
  22 /*
  23  * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
  24  * Use is subject to license terms.
  25  */
  26
  27 /*      Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
  28 /*        All Rights Reserved   */
  29
  30 /*
  31  * University Copyright- Copyright (c) 1982, 1986, 1988
  32  * The Regents of the University of California
  33  * All Rights Reserved
  34  *
  35  * University Acknowledgment- Portions of this document are derived from
  36  * software developed by the University of California, Berkeley, and its
  37  * contributors.
  38  */
  39
  40 #pragma ident   "%Z%%M% %I%     %E% SMI"
  41
  42 /*
  43  * rtime - get time from remote machine
  44  *
  45  * gets time, obtaining value from host
  46  * on the udp/time socket.  Since timeserver returns
  47  * with time of day in seconds since Jan 1, 1900,  must
  48  * subtract seconds before Jan 1, 1970 to get
  49  * what unix uses.
  50  */
  51
  52 #include <sys/types.h>
  53 #include <stdio.h>
  54 #include <string.h>
  55 #include <sys/socket.h>
  56 #include <sys/time.h>
  57 #include <errno.h>
  58 #include <netinet/in.h>
  59 #include <malloc.h>
  60
  61 #define NYEARS  (1970 - 1900)
  62 #define TOFFSET ((uint_t)60*60*24*(365*NYEARS + (NYEARS/4)))
  63
  64 extern int _socket(int, int, int);
  65 extern int _sendto(int, const char *, int, int,
  66         const struct sockaddr *, int);
  67 extern int _recvfrom(int, char *, int, int,
  68         struct sockaddr *, int *);
  69 extern int _connect(int, struct sockaddr *, int);
  70 extern int __rpc_dtbsize();
  71 extern ssize_t read(int, void *, size_t);
  72 extern int close(int);
  73 static void do_close();
  74
  75 int
  76 rtime(addrp, timep, timeout)
  77         struct sockaddr_in *addrp;
  78         struct timeval *timep;
  79         struct timeval *timeout;
  80 {
  81         int s;
  82         fd_set readfds;
  83         int res;
  84         uint_t thetime;
  85         struct sockaddr_in from;
  86         int fromlen;
  87         int type;
  88
  89         if (timeout == NULL) {
  90                 type = SOCK_STREAM;
  91         } else {
  92                 type = SOCK_DGRAM;
  93         }
  94         s = _socket(AF_INET, type, 0);
  95         if (s < 0) {
  96                 return (-1);
  97         }
  98         addrp->sin_family = AF_INET;
  99         addrp->sin_port = htons(IPPORT_TIMESERVER);
 100         if (type == SOCK_DGRAM) {
 101                 res = _sendto(s, (char *)&thetime, sizeof (thetime), 0,
 102                     (struct sockaddr *)addrp, sizeof (*addrp));
 103                 if (res < 0) {
 104                         do_close(s);
 105                         return (-1);
 106                 }
 107                 do {
 108                         FD_ZERO(&readfds);
 109                         FD_SET(s, &readfds);
 110                         res = select(__rpc_dtbsize(), &readfds, NULL,
 111                             NULL, timeout);
 112                 } while (res < 0 && errno == EINTR);
 113                 if (res <= 0) {
 114                         if (res == 0) {
 115                                 errno = ETIMEDOUT;
 116                         }
 117                         do_close(s);
 118                         return (-1);
 119                 }
 120                 fromlen = sizeof (from);
 121                 res = _recvfrom(s, (char *)&thetime, sizeof (thetime), 0,
 122                     (struct sockaddr *)&from, &fromlen);
 123                 do_close(s);
 124                 if (res < 0) {
 125                         return (-1);
 126                 }
 127         } else {
 128                 if (_connect(s, (struct sockaddr *)addrp,
 129                         sizeof (*addrp)) < 0) {
 130                         do_close(s);
 131                         return (-1);
 132                 }
 133                 res = read(s, (char *)&thetime, sizeof (thetime));
 134                 do_close(s);
 135                 if (res < 0) {
 136                         return (-1);
 137                 }
 138         }
 139         if (res != sizeof (thetime)) {
 140                 errno = EIO;
 141                 return (-1);
 142         }
 143         thetime = ntohl(thetime);
 144
 145         thetime = thetime - TOFFSET;
 146 #ifdef _ILP32
 147         if (thetime > INT32_MAX)
 148                 thetime = INT32_MAX;
 149 #endif
 150         timep->tv_sec = thetime;
 151         timep->tv_usec = 0;
 152         return (0);
 153 }
 154
 155 static void
 156 do_close(s)
 157         int s;
 158 {
 159         int save;
 160
 161         save = errno;
 162         (void) close(s);
 163         errno = save;
 164 }