bin/date/netdate.c

   1 /* $NetBSD: netdate.c,v 1.30 2011/01/29 02:16:52 christos Exp $ */
   2
   3 /*-
   4  * Copyright (c) 1990, 1993
   5  *      The Regents of the University of California.  All rights reserved.
   6  *
   7  * Redistribution and use in source and binary forms, with or without
   8  * modification, are permitted provided that the following conditions
   9  * are met:
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in the
  14  *    documentation and/or other materials provided with the distribution.
  15  * 3. Neither the name of the University nor the names of its contributors
  16  *    may be used to endorse or promote products derived from this software
  17  *    without specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  29  * SUCH DAMAGE.
  30  */
  31
  32 #include <sys/cdefs.h>
  33 #ifndef lint
  34 #if 0
  35 static char sccsid[] = "@(#)netdate.c   8.2 (Berkeley) 4/28/95";
  36 #else
  37 __RCSID("$NetBSD: netdate.c,v 1.30 2011/01/29 02:16:52 christos Exp $");
  38 #endif
  39 #endif /* not lint */
  40
  41 #include <sys/param.h>
  42 #include <sys/time.h>
  43 #include <sys/socket.h>
  44
  45 #include <netinet/in.h>
  46 #include <netdb.h>
  47 #define TSPTYPES
  48 #include <protocols/timed.h>
  49
  50 #include <err.h>
  51 #include <errno.h>
  52 #include <poll.h>
  53 #include <stdio.h>
  54 #include <string.h>
  55 #include <unistd.h>
  56
  57 #include "extern.h"
  58
  59 #define WAITACK         2000    /* milliseconds */
  60 #define WAITDATEACK     5000    /* milliseconds */
  61
  62 static const char *
  63 tsp_type_to_string(const struct tsp *msg)
  64 {
  65         unsigned i;
  66
  67         i = msg->tsp_type;
  68         return i < TSPTYPENUMBER ? tsptype[i] : "unknown";
  69 }
  70
  71 /*
  72  * Set the date in the machines controlled by timedaemons by communicating the
  73  * new date to the local timedaemon.  If the timedaemon is in the master state,
  74  * it performs the correction on all slaves.  If it is in the slave state, it
  75  * notifies the master that a correction is needed.
  76  * Returns 0 on success.  Returns > 0 on failure.
  77  */
  78 int
  79 netsettime(time_t tval)
  80 {
  81         struct sockaddr_in dest;
  82         struct tsp msg;
  83         char hostname[MAXHOSTNAMELEN];
  84         struct servent *sp;
  85         struct pollfd ready;
  86         int found, s, timed_ack, waittime;
  87
  88         if ((sp = getservbyname("timed", "udp")) == NULL) {
  89                 warnx("udp/timed: unknown service");
  90                 return 2;
  91         }
  92
  93         (void)memset(&dest, 0, sizeof(dest));
  94 #ifdef BSD4_4
  95         dest.sin_len = sizeof(dest);
  96 #endif
  97         dest.sin_family = AF_INET;
  98         dest.sin_port = sp->s_port;
  99         dest.sin_addr.s_addr = htonl(INADDR_ANY);
 100         s = socket(AF_INET, SOCK_DGRAM, 0);
 101         if (s == -1) {
 102                 if (errno != EAFNOSUPPORT)
 103                         warn("timed");
 104                 return 2;
 105         }
 106
 107 #ifdef IP_PORTRANGE
 108         {
 109                 static const int on = IP_PORTRANGE_LOW;
 110
 111                 if (setsockopt(s, IPPROTO_IP, IP_PORTRANGE, &on,
 112                     sizeof(on)) == -1) {
 113                         warn("setsockopt");
 114                         goto bad;
 115                 }
 116         }
 117 #endif
 118
 119         msg.tsp_type = TSP_SETDATE;
 120         msg.tsp_vers = TSPVERSION;
 121         if (gethostname(hostname, sizeof(hostname)) == -1) {
 122                 warn("gethostname");
 123                 goto bad;
 124         }
 125         (void)strlcpy(msg.tsp_name, hostname, sizeof(msg.tsp_name));
 126         msg.tsp_seq = htons((in_port_t)0);
 127         msg.tsp_time.tv_sec = htonl((in_addr_t)tval); /* XXX: y2038 */
 128         msg.tsp_time.tv_usec = htonl((in_addr_t)0);
 129         if (connect(s, (const void *)&dest, sizeof(dest)) == -1) {
 130                 warn("connect");
 131                 goto bad;
 132         }
 133         if (send(s, &msg, sizeof(msg), 0) == -1) {
 134                 if (errno != ECONNREFUSED)
 135                         warn("send");
 136                 goto bad;
 137         }
 138
 139         timed_ack = -1;
 140         waittime = WAITACK;
 141         ready.fd = s;
 142         ready.events = POLLIN;
 143 loop:
 144         found = poll(&ready, 1, waittime);
 145
 146         {
 147                 socklen_t len;
 148                 int error;
 149
 150                 len = sizeof(error);
 151                 if (getsockopt(s, SOL_SOCKET, SO_ERROR, &error, &len) == -1) {
 152                         warn("getsockopt");
 153                         goto bad;
 154                 }
 155                 if (error) {
 156                         if (error != ECONNREFUSED) {
 157                                 errno = error;
 158                                 warn("send (delayed error)");
 159                         }
 160                         goto bad;
 161                 }
 162         }
 163
 164         if (found > 0 && ready.revents & POLLIN) {
 165                 ssize_t ret;
 166
 167                 if ((ret = recv(s, &msg, sizeof(msg), 0)) == -1) {
 168                         if (errno != ECONNREFUSED)
 169                                 warn("recv");
 170                         goto bad;
 171                 } else if ((size_t)ret < sizeof(msg)) {
 172                         warnx("recv: incomplete packet");
 173                         goto bad;
 174                 }
 175
 176                 msg.tsp_seq = ntohs(msg.tsp_seq);
 177                 msg.tsp_time.tv_sec = ntohl(msg.tsp_time.tv_sec);
 178                 msg.tsp_time.tv_usec = ntohl(msg.tsp_time.tv_usec);
 179                 switch (msg.tsp_type) {
 180                 case TSP_ACK:
 181                         timed_ack = TSP_ACK;
 182                         waittime = WAITDATEACK;
 183                         goto loop;
 184                 case TSP_DATEACK:
 185                         (void)close(s);
 186                         return 0;
 187                 default:
 188                         warnx("wrong ack received from timed: %s",
 189                             tsp_type_to_string(&msg));
 190                         timed_ack = -1;
 191                         break;
 192                 }
 193         }
 194         if (timed_ack == -1)
 195                 warnx("can't reach time daemon, time set locally");
 196
 197 bad:
 198         (void)close(s);
 199         return 2;
 200 }