lib/libc/rpc/rtime.c

   1 /*-
   2  * Copyright (c) 2009, Sun Microsystems, Inc.
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions are met:
   7  * - Redistributions of source code must retain the above copyright notice,
   8  *   this list of conditions and the following disclaimer.
   9  * - Redistributions in binary form must reproduce the above copyright notice,
  10  *   this list of conditions and the following disclaimer in the documentation
  11  *   and/or other materials provided with the distribution.
  12  * - Neither the name of Sun Microsystems, Inc. nor the names of its
  13  *   contributors may be used to endorse or promote products derived
  14  *   from this software without specific prior written permission.
  15  *
  16  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  17  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  19  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
  20  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  21  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  22  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  23  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  24  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  25  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  26  * POSSIBILITY OF SUCH DAMAGE.
  27  *
  28  * @(#)rtime.c  2.2 88/08/10 4.0 RPCSRC; from 1.8 88/02/08 SMI
  29  * $FreeBSD: src/lib/libc/rpc/rtime.c,v 1.9 2005/03/10 00:57:01 stefanf Exp $
  30  * $DragonFly: src/lib/libc/rpc/rtime.c,v 1.5 2005/11/13 12:27:04 swildner Exp $
  31  */
  32
  33 /*
  34  * Copyright (c) 1988 by Sun Microsystems, Inc.
  35  */
  36
  37 /*
  38  * rtime - get time from remote machine
  39  *
  40  * gets time, obtaining value from host
  41  * on the udp/time socket.  Since timeserver returns
  42  * with time of day in seconds since Jan 1, 1900,  must
  43  * subtract seconds before Jan 1, 1970 to get
  44  * what unix uses.
  45  */
  46 #include "namespace.h"
  47 #include <stdlib.h>
  48 #include <string.h>
  49 #include <unistd.h>
  50 #include <errno.h>
  51 #include <sys/types.h>
  52 #include <sys/socket.h>
  53 #include <sys/time.h>
  54 #include <netinet/in.h>
  55 #include <stdio.h>
  56 #include <netdb.h>
  57 #include "un-namespace.h"
  58
  59 extern int _rpc_dtablesize(void);
  60
  61 #define NYEARS  (unsigned long)(1970 - 1900)
  62 #define TOFFSET (unsigned long)(60*60*24*(365*NYEARS + (NYEARS/4)))
  63
  64 static void do_close(int);
  65
  66 int
  67 rtime(struct sockaddr_in *addrp, struct timeval *timep, struct timeval *timeout)
  68 {
  69         int s;
  70         fd_set readfds;
  71         int res;
  72         unsigned long thetime;
  73         struct sockaddr_in from;
  74         socklen_t fromlen;
  75         int type;
  76         struct servent *serv;
  77
  78         if (timeout == NULL) {
  79                 type = SOCK_STREAM;
  80         } else {
  81                 type = SOCK_DGRAM;
  82         }
  83         s = _socket(AF_INET, type, 0);
  84         if (s < 0) {
  85                 return(-1);
  86         }
  87         addrp->sin_family = AF_INET;
  88
  89         /* TCP and UDP port are the same in this case */
  90         if ((serv = getservbyname("time", "tcp")) == NULL) {
  91                 return(-1);
  92         }
  93
  94         addrp->sin_port = serv->s_port;
  95
  96         if (type == SOCK_DGRAM) {
  97                 res = _sendto(s, (char *)&thetime, sizeof(thetime), 0,
  98                              (struct sockaddr *)addrp, sizeof(*addrp));
  99                 if (res < 0) {
 100                         do_close(s);
 101                         return(-1);
 102                 }
 103                 do {
 104                         FD_ZERO(&readfds);
 105                         FD_SET(s, &readfds);
 106                         res = _select(_rpc_dtablesize(), &readfds,
 107                                      NULL, NULL, timeout);
 108                 } while (res < 0 && errno == EINTR);
 109                 if (res <= 0) {
 110                         if (res == 0) {
 111                                 errno = ETIMEDOUT;
 112                         }
 113                         do_close(s);
 114                         return(-1);
 115                 }
 116                 fromlen = sizeof(from);
 117                 res = _recvfrom(s, (char *)&thetime, sizeof(thetime), 0,
 118                                (struct sockaddr *)&from, &fromlen);
 119                 do_close(s);
 120                 if (res < 0) {
 121                         return(-1);
 122                 }
 123         } else {
 124                 if (_connect(s, (struct sockaddr *)addrp, sizeof(*addrp)) < 0) {
 125                         do_close(s);
 126                         return(-1);
 127                 }
 128                 res = _read(s, (char *)&thetime, sizeof(thetime));
 129                 do_close(s);
 130                 if (res < 0) {
 131                         return(-1);
 132                 }
 133         }
 134         if (res != sizeof(thetime)) {
 135                 errno = EIO;
 136                 return(-1);
 137         }
 138         thetime = ntohl(thetime);
 139         timep->tv_sec = thetime - TOFFSET;
 140         timep->tv_usec = 0;
 141         return(0);
 142 }
 143
 144 static void
 145 do_close(int s)
 146 {
 147         int save;
 148
 149         save = errno;
 150         _close(s);
 151         errno = save;
 152 }