1 #if 0
2 static char sccsid[] = "@(#)rtime.c	2.2 88/08/10 4.0 RPCSRC; from 1.8 88/02/08 SMI";
3 #endif
4 /*
5  * Sun RPC is a product of Sun Microsystems, Inc. and is provided for
6  * unrestricted use provided that this legend is included on all tape
7  * media and as a part of the software program in whole or part.  Users
8  * may copy or modify Sun RPC without charge, but are not authorized
9  * to license or distribute it to anyone else except as part of a product or
10  * program developed by the user.
11  *
12  * SUN RPC IS PROVIDED AS IS WITH NO WARRANTIES OF ANY KIND INCLUDING THE
13  * WARRANTIES OF DESIGN, MERCHANTIBILITY AND FITNESS FOR A PARTICULAR
14  * PURPOSE, OR ARISING FROM A COURSE OF DEALING, USAGE OR TRADE PRACTICE.
15  *
16  * Sun RPC is provided with no support and without any obligation on the
17  * part of Sun Microsystems, Inc. to assist in its use, correction,
18  * modification or enhancement.
19  *
20  * SUN MICROSYSTEMS, INC. SHALL HAVE NO LIABILITY WITH RESPECT TO THE
21  * INFRINGEMENT OF COPYRIGHTS, TRADE SECRETS OR ANY PATENTS BY SUN RPC
22  * OR ANY PART THEREOF.
23  *
24  * In no event will Sun Microsystems, Inc. be liable for any lost revenue
25  * or profits or other special, indirect and consequential damages, even if
26  * Sun has been advised of the possibility of such damages.
27  *
28  * Sun Microsystems, Inc.
29  * 2550 Garcia Avenue
30  * Mountain View, California  94043
31  */
32 
33 /*
34  * Copyright (c) 1988 by Sun Microsystems, Inc.
35  */
36 /*
37  * rtime - get time from remote machine
38  *
39  * gets time, obtaining value from host
40  * on the udp/time socket.  Since timeserver returns
41  * with time of day in seconds since Jan 1, 1900,  must
42  * subtract seconds before Jan 1, 1970 to get
43  * what unix uses.
44  */
45 
46 #include <stdio.h>
47 #include <unistd.h>
48 #include <rpc/rpc.h>
49 #include <rpc/clnt.h>
50 #include <sys/types.h>
51 #include <sys/poll.h>
52 #include <sys/socket.h>
53 #include <sys/time.h>
54 #include <rpc/auth_des.h>
55 #include <errno.h>
56 #include <netinet/in.h>
57 
58 
59 #define NYEARS	(u_long)(1970 - 1900)
60 #define TOFFSET (u_long)(60*60*24*(365*NYEARS + (NYEARS/4)))
61 
62 static void do_close (int);
63 
64 static void
do_close(int s)65 do_close (int s)
66 {
67   int save;
68 
69   save = errno;
70   close (s);
71   __set_errno (save);
72 }
73 
74 int
rtime(struct sockaddr_in * addrp,struct rpc_timeval * timep,struct rpc_timeval * timeout)75 rtime (struct sockaddr_in *addrp, struct rpc_timeval *timep,
76        struct rpc_timeval *timeout)
77 {
78   int s;
79   struct pollfd fd;
80   int milliseconds;
81   int res;
82   /* RFC 868 says the time is transmitted as a 32-bit value.  */
83   uint32_t thetime;
84   struct sockaddr_in from;
85   socklen_t fromlen;
86   int type;
87 
88   if (timeout == NULL)
89     type = SOCK_STREAM;
90   else
91     type = SOCK_DGRAM;
92 
93   s = socket (AF_INET, type, 0);
94   if (s < 0)
95     return (-1);
96 
97   addrp->sin_family = AF_INET;
98   addrp->sin_port = htons (IPPORT_TIMESERVER);
99   if (type == SOCK_DGRAM)
100     {
101       res = sendto (s, (char *) &thetime, sizeof (thetime), 0,
102 		      (struct sockaddr *) addrp, sizeof (*addrp));
103       if (res < 0)
104 	{
105 	  do_close (s);
106 	  return -1;
107 	}
108       milliseconds = (timeout->tv_sec * 1000) + (timeout->tv_usec / 1000);
109       fd.fd = s;
110       fd.events = POLLIN;
111       do
112 	res = poll (&fd, 1, milliseconds);
113       while (res < 0 && errno == EINTR);
114       if (res <= 0)
115 	{
116 	  if (res == 0)
117 	    __set_errno (ETIMEDOUT);
118 	  do_close (s);
119 	  return (-1);
120 	}
121       fromlen = sizeof (from);
122       res = recvfrom (s, (char *) &thetime, sizeof (thetime), 0,
123 			(struct sockaddr *) &from, &fromlen);
124       do_close (s);
125       if (res < 0)
126 	return -1;
127     }
128   else
129     {
130       if (connect (s, (struct sockaddr *) addrp, sizeof (*addrp)) < 0)
131 	{
132 	  do_close (s);
133 	  return -1;
134 	}
135       res = read (s, (char *) &thetime, sizeof (thetime));
136       do_close (s);
137       if (res < 0)
138 	return (-1);
139     }
140   if (res != sizeof (thetime))
141     {
142       __set_errno (EIO);
143       return -1;
144     }
145   thetime = ntohl (thetime);
146   timep->tv_sec = thetime - TOFFSET;
147   timep->tv_usec = 0;
148   return 0;
149 }
150