bin/date/netdate.c

   1 /*-
   2  * Copyright (c) 1990, 1993
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. All advertising materials mentioning features or use of this software
  14  *    must display the following acknowledgement:
  15  *      This product includes software developed by the University of
  16  *      California, Berkeley and its contributors.
  17  * 4. Neither the name of the University nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  *
  33  * @(#)netdate.c        8.1 (Berkeley) 5/31/93
  34  * $FreeBSD: src/bin/date/netdate.c,v 1.18 2004/04/06 20:06:45 markm Exp $
  35  * $DragonFly: src/bin/date/netdate.c,v 1.7 2005/07/20 06:25:20 cpressey Exp $
  36  */
  37
  38 #include <sys/param.h>
  39 #include <sys/time.h>
  40 #include <sys/socket.h>
  41
  42 #include <netinet/in.h>
  43 #include <netdb.h>
  44 #define TSPTYPES
  45 #include <protocols/timed.h>
  46
  47 #include <err.h>
  48 #include <errno.h>
  49 #include <string.h>
  50 #include <unistd.h>
  51
  52 #include "extern.h"
  53
  54 #define WAITACK         2       /* seconds */
  55 #define WAITDATEACK     5       /* seconds */
  56
  57 extern int retval;
  58
  59 /*
  60  * Set the date in the machines controlled by timedaemons by communicating the
  61  * new date to the local timedaemon.  If the timedaemon is in the master state,
  62  * it performs the correction on all slaves.  If it is in the slave state, it
  63  * notifies the master that a correction is needed.
  64  * Returns 0 on success.  Returns > 0 on failure, setting retval to 2;
  65  */
  66 int
  67 netsettime(time_t tval)
  68 {
  69         struct timeval tout;
  70         struct servent *sp;
  71         struct tsp msg;
  72         struct sockaddr_in tmpsin, dest, from;
  73         fd_set ready;
  74         long waittime;
  75         int s, port, timed_ack, found, errn;
  76         size_t length;
  77         char hostname[MAXHOSTNAMELEN];
  78
  79         if ((sp = getservbyname("timed", "udp")) == NULL) {
  80                 warnx("timed/udp: unknown service");
  81                 return (retval = 2);
  82         }
  83
  84         dest.sin_port = sp->s_port;
  85         dest.sin_family = AF_INET;
  86         dest.sin_addr.s_addr = htonl((u_long)INADDR_ANY);
  87         s = socket(AF_INET, SOCK_DGRAM, 0);
  88         if (s < 0) {
  89                 if (errno != EPROTONOSUPPORT)
  90                         warn("timed");
  91                 return (retval = 2);
  92         }
  93
  94         memset(&tmpsin, 0, sizeof(tmpsin));
  95         tmpsin.sin_family = AF_INET;
  96         for (port = IPPORT_RESERVED - 1; port > IPPORT_RESERVED / 2; port--) {
  97                 tmpsin.sin_port = htons((u_short)port);
  98                 if (bind(s, (struct sockaddr *)&tmpsin, sizeof(tmpsin)) >= 0)
  99                         break;
 100                 if (errno == EADDRINUSE)
 101                         continue;
 102                 if (errno != EADDRNOTAVAIL)
 103                         warn("bind");
 104                 goto bad;
 105         }
 106         if (port == IPPORT_RESERVED / 2) {
 107                 warnx("all ports in use");
 108                 goto bad;
 109         }
 110         msg.tsp_type = TSP_SETDATE;
 111         msg.tsp_vers = TSPVERSION;
 112         if (gethostname(hostname, sizeof(hostname))) {
 113                 warn("gethostname");
 114                 goto bad;
 115         }
 116         strncpy(msg.tsp_name, hostname, sizeof(msg.tsp_name) - 1);
 117         msg.tsp_name[sizeof(msg.tsp_name) - 1] = '\0';
 118         msg.tsp_seq = htons((u_short)0);
 119         msg.tsp_time.tv_sec = htonl((u_long)tval);
 120         msg.tsp_time.tv_usec = htonl((u_long)0);
 121         length = sizeof(struct sockaddr_in);
 122         if (connect(s, (struct sockaddr *)&dest, length) < 0) {
 123                 warn("connect");
 124                 goto bad;
 125         }
 126         if (send(s, (char *)&msg, sizeof(struct tsp), 0) < 0) {
 127                 if (errno != ECONNREFUSED)
 128                         warn("send");
 129                 goto bad;
 130         }
 131
 132         timed_ack = -1;
 133         waittime = WAITACK;
 134 loop:
 135         tout.tv_sec = waittime;
 136         tout.tv_usec = 0;
 137
 138         FD_ZERO(&ready);
 139         FD_SET(s, &ready);
 140         found = select(FD_SETSIZE, &ready, (fd_set *)0, (fd_set *)0, &tout);
 141
 142         length = sizeof(errn);
 143         if (!getsockopt(s,
 144             SOL_SOCKET, SO_ERROR, (char *)&errn, &length) && errn) {
 145                 if (errn != ECONNREFUSED)
 146                         warnc(errn, "send (delayed error)");
 147                 goto bad;
 148         }
 149
 150         if (found > 0 && FD_ISSET(s, &ready)) {
 151                 length = sizeof(struct sockaddr_in);
 152                 if (recvfrom(s, &msg, sizeof(struct tsp), 0,
 153                     (struct sockaddr *)&from, &length) < 0) {
 154                         if (errno != ECONNREFUSED)
 155                                 warn("recvfrom");
 156                         goto bad;
 157                 }
 158                 msg.tsp_seq = ntohs(msg.tsp_seq);
 159                 msg.tsp_time.tv_sec = ntohl(msg.tsp_time.tv_sec);
 160                 msg.tsp_time.tv_usec = ntohl(msg.tsp_time.tv_usec);
 161                 switch (msg.tsp_type) {
 162                 case TSP_ACK:
 163                         timed_ack = TSP_ACK;
 164                         waittime = WAITDATEACK;
 165                         goto loop;
 166                 case TSP_DATEACK:
 167                         close(s);
 168                         return (0);
 169                 default:
 170                         warnx("wrong ack received from timed: %s",
 171                             tsptype[msg.tsp_type]);
 172                         timed_ack = -1;
 173                         break;
 174                 }
 175         }
 176         if (timed_ack == -1)
 177                 warnx("can't reach time daemon, time set locally");
 178
 179 bad:
 180         close(s);
 181         return (retval = 2);
 182 }