lib/libc/rpc/rtime.c

   1 /*
   2  * Sun RPC is a product of Sun Microsystems, Inc. and is provided for
   3  * unrestricted use provided that this legend is included on all tape
   4  * media and as a part of the software program in whole or part.  Users
   5  * may copy or modify Sun RPC without charge, but are not authorized
   6  * to license or distribute it to anyone else except as part of a product or
   7  * program developed by the user.
   8  *
   9  * SUN RPC IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING THE
  10  * WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR
  11  * PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE.
  12  *
  13  * Sun RPC is provided with no support and without any obligation on the
  14  * part of Sun Microsystems, Inc. to assist in its use, correction,
  15  * modification or enhancement.
  16  *
  17  * SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE
  18  * INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY SUN RPC
  19  * OR ANY PART THEREOF.
  20  *
  21  * In no event will Sun Microsystems, Inc. be liable for any lost revenue
  22  * or profits or other special, indirect and consequential damages, even if
  23  * Sun has been advised of the possibility of such damages.
  24  *
  25  * Sun Microsystems, Inc.
  26  * 2550 Garcia Avenue
  27  * Mountain View, California  94043
  28  *
  29  * @(#)rtime.c  2.2 88/08/10 4.0 RPCSRC; from 1.8 88/02/08 SMI
  30  * $FreeBSD: src/lib/libc/rpc/rtime.c,v 1.5 2000/01/27 23:06:41 jasone Exp $
  31  * $DragonFly: src/lib/libc/rpc/rtime.c,v 1.5 2005/11/13 12:27:04 swildner Exp $
  32  */
  33
  34 /*
  35  * Copyright (c) 1988 by Sun Microsystems, Inc.
  36
  37  */
  38
  39 /*
  40  * rtime - get time from remote machine
  41  *
  42  * gets time, obtaining value from host
  43  * on the udp/time socket.  Since timeserver returns
  44  * with time of day in seconds since Jan 1, 1900,  must
  45  * subtract seconds before Jan 1, 1970 to get
  46  * what unix uses.
  47  */
  48 #include "namespace.h"
  49 #include <stdlib.h>
  50 #include <string.h>
  51 #include <unistd.h>
  52 #include <errno.h>
  53 #include <sys/types.h>
  54 #include <sys/socket.h>
  55 #include <sys/time.h>
  56 #include <netinet/in.h>
  57 #include <stdio.h>
  58 #include <netdb.h>
  59 #include "un-namespace.h"
  60
  61 extern int _rpc_dtablesize ( void );
  62
  63 #define NYEARS  (unsigned long)(1970 - 1900)
  64 #define TOFFSET (unsigned long)(60*60*24*(365*NYEARS + (NYEARS/4)))
  65
  66 static void do_close ( int );
  67
  68 int
  69 rtime(struct sockaddr_in *addrp, struct timeval *timep, struct timeval *timeout)
  70 {
  71         int s;
  72         fd_set readfds;
  73         int res;
  74         unsigned long thetime;
  75         struct sockaddr_in from;
  76         int fromlen;
  77         int type;
  78         struct servent *serv;
  79
  80         if (timeout == NULL) {
  81                 type = SOCK_STREAM;
  82         } else {
  83                 type = SOCK_DGRAM;
  84         }
  85         s = _socket(AF_INET, type, 0);
  86         if (s < 0) {
  87                 return(-1);
  88         }
  89         addrp->sin_family = AF_INET;
  90
  91         /* TCP and UDP port are the same in this case */
  92         if ((serv = getservbyname("time", "tcp")) == NULL) {
  93                 return(-1);
  94         }
  95
  96         addrp->sin_port = serv->s_port;
  97
  98         if (type == SOCK_DGRAM) {
  99                 res = _sendto(s, (char *)&thetime, sizeof(thetime), 0,
 100                              (struct sockaddr *)addrp, sizeof(*addrp));
 101                 if (res < 0) {
 102                         do_close(s);
 103                         return(-1);
 104                 }
 105                 do {
 106                         FD_ZERO(&readfds);
 107                         FD_SET(s, &readfds);
 108                         res = _select(_rpc_dtablesize(), &readfds,
 109                                      (fd_set *)NULL, (fd_set *)NULL, timeout);
 110                 } while (res < 0 && errno == EINTR);
 111                 if (res <= 0) {
 112                         if (res == 0) {
 113                                 errno = ETIMEDOUT;
 114                         }
 115                         do_close(s);
 116                         return(-1);
 117                 }
 118                 fromlen = sizeof(from);
 119                 res = _recvfrom(s, (char *)&thetime, sizeof(thetime), 0,
 120                                (struct sockaddr *)&from, &fromlen);
 121                 do_close(s);
 122                 if (res < 0) {
 123                         return(-1);
 124                 }
 125         } else {
 126                 if (_connect(s, (struct sockaddr *)addrp, sizeof(*addrp)) < 0) {
 127                         do_close(s);
 128                         return(-1);
 129                 }
 130                 res = _read(s, (char *)&thetime, sizeof(thetime));
 131                 do_close(s);
 132                 if (res < 0) {
 133                         return(-1);
 134                 }
 135         }
 136         if (res != sizeof(thetime)) {
 137                 errno = EIO;
 138                 return(-1);
 139         }
 140         thetime = ntohl(thetime);
 141         timep->tv_sec = thetime - TOFFSET;
 142         timep->tv_usec = 0;
 143         return(0);
 144 }
 145
 146 static void
 147 do_close(int s)
 148 {
 149         int save;
 150
 151         save = errno;
 152         _close(s);
 153         errno = save;
 154 }