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