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 1.9 2005/03/10 00:57:01 stefanf 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  * rtime - get time from remote machine
  40  *
  41  * gets time, obtaining value from host
  42  * on the udp/time socket.  Since timeserver returns
  43  * with time of day in seconds since Jan 1, 1900,  must
  44  * subtract seconds before Jan 1, 1970 to get
  45  * what unix uses.
  46  */
  47 #include "namespace.h"
  48 #include <stdlib.h>
  49 #include <string.h>
  50 #include <unistd.h>
  51 #include <errno.h>
  52 #include <sys/types.h>
  53 #include <sys/socket.h>
  54 #include <sys/time.h>
  55 #include <netinet/in.h>
  56 #include <stdio.h>
  57 #include <netdb.h>
  58 #include "un-namespace.h"
  59
  60 extern int _rpc_dtablesize(void);
  61
  62 #define NYEARS  (unsigned long)(1970 - 1900)
  63 #define TOFFSET (unsigned long)(60*60*24*(365*NYEARS + (NYEARS/4)))
  64
  65 static void do_close(int);
  66
  67 int
  68 rtime(struct sockaddr_in *addrp, struct timeval *timep, struct timeval *timeout)
  69 {
  70         int s;
  71         fd_set readfds;
  72         int res;
  73         unsigned long thetime;
  74         struct sockaddr_in from;
  75         socklen_t fromlen;
  76         int type;
  77         struct servent *serv;
  78
  79         if (timeout == NULL) {
  80                 type = SOCK_STREAM;
  81         } else {
  82                 type = SOCK_DGRAM;
  83         }
  84         s = _socket(AF_INET, type, 0);
  85         if (s < 0) {
  86                 return(-1);
  87         }
  88         addrp->sin_family = AF_INET;
  89
  90         /* TCP and UDP port are the same in this case */
  91         if ((serv = getservbyname("time", "tcp")) == NULL) {
  92                 return(-1);
  93         }
  94
  95         addrp->sin_port = serv->s_port;
  96
  97         if (type == SOCK_DGRAM) {
  98                 res = _sendto(s, (char *)&thetime, sizeof(thetime), 0,
  99                              (struct sockaddr *)addrp, sizeof(*addrp));
 100                 if (res < 0) {
 101                         do_close(s);
 102                         return(-1);
 103                 }
 104                 do {
 105                         FD_ZERO(&readfds);
 106                         FD_SET(s, &readfds);
 107                         res = _select(_rpc_dtablesize(), &readfds,
 108                                      (fd_set *)NULL, (fd_set *)NULL, timeout);
 109                 } while (res < 0 && errno == EINTR);
 110                 if (res <= 0) {
 111                         if (res == 0) {
 112                                 errno = ETIMEDOUT;
 113                         }
 114                         do_close(s);
 115                         return(-1);
 116                 }
 117                 fromlen = sizeof(from);
 118                 res = _recvfrom(s, (char *)&thetime, sizeof(thetime), 0,
 119                                (struct sockaddr *)&from, &fromlen);
 120                 do_close(s);
 121                 if (res < 0) {
 122                         return(-1);
 123                 }
 124         } else {
 125                 if (_connect(s, (struct sockaddr *)addrp, sizeof(*addrp)) < 0) {
 126                         do_close(s);
 127                         return(-1);
 128                 }
 129                 res = _read(s, (char *)&thetime, sizeof(thetime));
 130                 do_close(s);
 131                 if (res < 0) {
 132                         return(-1);
 133                 }
 134         }
 135         if (res != sizeof(thetime)) {
 136                 errno = EIO;
 137                 return(-1);
 138         }
 139         thetime = ntohl(thetime);
 140         timep->tv_sec = thetime - TOFFSET;
 141         timep->tv_usec = 0;
 142         return(0);
 143 }
 144
 145 static void
 146 do_close(int s)
 147 {
 148         int save;
 149
 150         save = errno;
 151         _close(s);
 152         errno = save;
 153 }