bin/date/netdate.c

   1 /* $NetBSD: netdate.c,v 1.26 2007/02/04 22:21:53 cbiere 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 1.26 2007/02/04 22:21:53 cbiere 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 extern int retval;
  63
  64 static const char *
  65 tsp_type_to_string(const struct tsp *msg)
  66 {
  67         unsigned i;
  68
  69         i = msg->tsp_type;
  70         return i < TSPTYPENUMBER ? tsptype[i] : "unknown";
  71 }
  72
  73 /*
  74  * Set the date in the machines controlled by timedaemons by communicating the
  75  * new date to the local timedaemon.  If the timedaemon is in the master state,
  76  * it performs the correction on all slaves.  If it is in the slave state, it
  77  * notifies the master that a correction is needed.
  78  * Returns 0 on success.  Returns > 0 on failure, setting retval to 2;
  79  */
  80 int
  81 netsettime(time_t tval)
  82 {
  83         struct sockaddr_in dest;
  84         struct tsp msg;
  85         char hostname[MAXHOSTNAMELEN];
  86         struct servent *sp;
  87         struct pollfd ready;
  88         int found, s, timed_ack, waittime;
  89
  90         if ((sp = getservbyname("timed", "udp")) == NULL) {
  91                 warnx("udp/timed: unknown service");
  92                 return (retval = 2);
  93         }
  94
  95         (void)memset(&dest, 0, sizeof(dest));
  96 #ifdef BSD4_4
  97         dest.sin_len = sizeof(dest);
  98 #endif
  99         dest.sin_family = AF_INET;
 100         dest.sin_port = sp->s_port;
 101         dest.sin_addr.s_addr = htonl(INADDR_ANY);
 102         s = socket(AF_INET, SOCK_DGRAM, 0);
 103         if (s < 0) {
 104                 if (errno != EAFNOSUPPORT)
 105                         warn("timed");
 106                 return (retval = 2);
 107         }
 108
 109 #ifdef IP_PORTRANGE
 110         {
 111                 static const int on = IP_PORTRANGE_LOW;
 112
 113                 if (setsockopt(s, IPPROTO_IP, IP_PORTRANGE,
 114                             &on, sizeof(on)) < 0) {
 115                         warn("setsockopt");
 116                         goto bad;
 117                 }
 118         }
 119 #endif
 120
 121         msg.tsp_type = TSP_SETDATE;
 122         msg.tsp_vers = TSPVERSION;
 123         if (gethostname(hostname, sizeof(hostname))) {
 124                 warn("gethostname");
 125                 goto bad;
 126         }
 127         strncpy(msg.tsp_name, hostname, sizeof(msg.tsp_name));
 128         msg.tsp_name[sizeof(msg.tsp_name) - 1] = '\0';
 129         msg.tsp_seq = htons((uint16_t)0);
 130         msg.tsp_time.tv_sec = htonl((uint32_t)tval); /* XXX: y2038 */
 131         msg.tsp_time.tv_usec = htonl((uint32_t)0);
 132         if (connect(s, (const struct sockaddr *)&dest, sizeof(dest)) < 0) {
 133                 warn("connect");
 134                 goto bad;
 135         }
 136         if (send(s, &msg, sizeof(msg), 0) < 0) {
 137                 if (errno != ECONNREFUSED)
 138                         warn("send");
 139                 goto bad;
 140         }
 141
 142         timed_ack = -1;
 143         waittime = WAITACK;
 144         ready.fd = s;
 145         ready.events = POLLIN;
 146 loop:
 147         found = poll(&ready, 1, waittime);
 148
 149         {
 150                 socklen_t length;
 151                 int error;
 152
 153                 length = sizeof(error);
 154                 if (!getsockopt(s, SOL_SOCKET, SO_ERROR, &error, &length)
 155                     && error) {
 156                         if (error != ECONNREFUSED)
 157                                 warn("send (delayed error)");
 158                         goto bad;
 159                 }
 160         }
 161
 162         if (found > 0 && ready.revents & POLLIN) {
 163                 ssize_t ret;
 164
 165                 ret = recv(s, &msg, sizeof(msg), 0);
 166                 if (ret < 0) {
 167                         if (errno != ECONNREFUSED)
 168                                 warn("recv");
 169                         goto bad;
 170                 } else if ((size_t)ret < sizeof(msg)) {
 171                         warnx("recv: incomplete packet");
 172                         goto bad;
 173                 }
 174
 175                 msg.tsp_seq = ntohs(msg.tsp_seq);
 176                 msg.tsp_time.tv_sec = ntohl(msg.tsp_time.tv_sec);
 177                 msg.tsp_time.tv_usec = ntohl(msg.tsp_time.tv_usec);
 178                 switch (msg.tsp_type) {
 179                 case TSP_ACK:
 180                         timed_ack = TSP_ACK;
 181                         waittime = WAITDATEACK;
 182                         goto loop;
 183                 case TSP_DATEACK:
 184                         (void)close(s);
 185                         return (0);
 186                 default:
 187                         warnx("wrong ack received from timed: %s",
 188                             tsp_type_to_string(&msg));
 189                         timed_ack = -1;
 190                         break;
 191                 }
 192         }
 193         if (timed_ack == -1)
 194                 warnx("can't reach time daemon, time set locally");
 195
 196 bad:
 197         (void)close(s);
 198         return (retval = 2);
 199 }