1/*
2 * Copyright (c) 2010, Oracle America, Inc.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions are
6 * met:
7 *
8 * * Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * * Redistributions in binary form must reproduce the above
11 * copyright notice, this list of conditions and the following
12 * disclaimer in the documentation and/or other materials
13 * provided with the distribution.
14 * * Neither the name of the "Oracle America, Inc." nor the names of its
15 * contributors may be used to endorse or promote products derived
16 * from this software without specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
19 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
20 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
21 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
22 * COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
23 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
25 * GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
27 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
28 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
29 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30 */
31/*
32 * rtime - get time from remote machine
33 *
34 * gets time, obtaining value from host
35 * on the udp/time socket. Since timeserver returns
36 * with time of day in seconds since Jan 1, 1900, must
37 * subtract seconds before Jan 1, 1970 to get
38 * what unix uses.
39 */
40#include <stdio.h>
41#include <unistd.h>
42#include <stdint.h>
43#include <rpc/rpc.h>
44#include <rpc/clnt.h>
45#include <sys/types.h>
46#include <sys/poll.h>
47#include <sys/socket.h>
48#include <sys/time.h>
49#include <rpc/auth_des.h>
50#include <errno.h>
51#include <netinet/in.h>
52#include <shlib-compat.h>
53
54#define NYEARS (u_long)(1970 - 1900)
55#define TOFFSET (u_long)(60*60*24*(365*NYEARS + (NYEARS/4)))
56
57static void do_close (int);
58
59static void
60do_close (int s)
61{
62 int save;
63
64 save = errno;
65 __close (s);
66 __set_errno (save);
67}
68
69int
70rtime (struct sockaddr_in *addrp, struct rpc_timeval *timep,
71 struct rpc_timeval *timeout)
72{
73 int s;
74 struct pollfd fd;
75 int milliseconds;
76 int res;
77 /* RFC 868 says the time is transmitted as a 32-bit value. */
78 uint32_t thetime;
79 struct sockaddr_in from;
80 socklen_t fromlen;
81 int type;
82
83 if (timeout == NULL)
84 type = SOCK_STREAM;
85 else
86 type = SOCK_DGRAM;
87
88 s = __socket (AF_INET, type, 0);
89 if (s < 0)
90 return (-1);
91
92 addrp->sin_family = AF_INET;
93 addrp->sin_port = htons (IPPORT_TIMESERVER);
94 if (type == SOCK_DGRAM)
95 {
96 res = __sendto (fd: s, buf: (char *) &thetime, n: sizeof (thetime), flags: 0,
97 addr: (struct sockaddr *) addrp, addr_len: sizeof (*addrp));
98 if (res < 0)
99 {
100 do_close (s);
101 return -1;
102 }
103 milliseconds = (timeout->tv_sec * 1000) + (timeout->tv_usec / 1000);
104 fd.fd = s;
105 fd.events = POLLIN;
106 do
107 res = __poll (&fd, 1, milliseconds);
108 while (res < 0 && errno == EINTR);
109 if (res <= 0)
110 {
111 if (res == 0)
112 __set_errno (ETIMEDOUT);
113 do_close (s);
114 return (-1);
115 }
116 fromlen = sizeof (from);
117 res = __recvfrom (fd: s, buf: (char *) &thetime, n: sizeof (thetime), flags: 0,
118 addr: (struct sockaddr *) &from, addr_len: &fromlen);
119 do_close (s);
120 if (res < 0)
121 return -1;
122 }
123 else
124 {
125 if (__connect (s, (struct sockaddr *) addrp, sizeof (*addrp)) < 0)
126 {
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 if (res != sizeof (thetime))
136 {
137 __set_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}
145libc_hidden_nolink_sunrpc (rtime, GLIBC_2_1)
146

source code of glibc/sunrpc/rtime.c