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: src/bin/date/netdate.c,v 1.18 2004/04/06 20:06:45 markm Exp $");
  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 extern int retval;
  59
  60 /*
  61  * Set the date in the machines controlled by timedaemons by communicating the
  62  * new date to the local timedaemon.  If the timedaemon is in the master state,
  63  * it performs the correction on all slaves.  If it is in the slave state, it
  64  * notifies the master that a correction is needed.
  65  * Returns 0 on success.  Returns > 0 on failure, setting retval to 2;
  66  */
  67 int
  68 netsettime(time_t tval)
  69 {
  70         struct timeval tout;
  71         struct servent *sp;
  72         struct tsp msg;
  73         struct sockaddr_in lsin, dest, from;
  74         fd_set ready;
  75         long waittime;
  76         int s, port, timed_ack, found, lerr;
  77         socklen_t length;
  78         char hostname[MAXHOSTNAMELEN];
  79
  80         if ((sp = getservbyname("timed", "udp")) == NULL) {
  81                 warnx("timed/udp: unknown service");
  82                 return (retval = 2);
  83         }
  84
  85         dest.sin_port = sp->s_port;
  86         dest.sin_family = AF_INET;
  87         dest.sin_addr.s_addr = htonl((u_long)INADDR_ANY);
  88         s = socket(AF_INET, SOCK_DGRAM, 0);
  89         if (s < 0) {
  90                 if (errno != EPROTONOSUPPORT)
  91                         warn("timed");
  92                 return (retval = 2);
  93         }
  94
  95         memset(&lsin, 0, sizeof(lsin));
  96         lsin.sin_family = AF_INET;
  97         for (port = IPPORT_RESERVED - 1; port > IPPORT_RESERVED / 2; port--) {
  98                 lsin.sin_port = htons((u_short)port);
  99                 if (bind(s, (struct sockaddr *)&lsin, sizeof(lsin)) >= 0)
 100                         break;
 101                 if (errno == EADDRINUSE)
 102                         continue;
 103                 if (errno != EADDRNOTAVAIL)
 104                         warn("bind");
 105                 goto bad;
 106         }
 107         if (port == IPPORT_RESERVED / 2) {
 108                 warnx("all ports in use");
 109                 goto bad;
 110         }
 111         msg.tsp_type = TSP_SETDATE;
 112         msg.tsp_vers = TSPVERSION;
 113         if (gethostname(hostname, sizeof(hostname))) {
 114                 warn("gethostname");
 115                 goto bad;
 116         }
 117         (void)strncpy(msg.tsp_name, hostname, sizeof(msg.tsp_name) - 1);
 118         msg.tsp_name[sizeof(msg.tsp_name) - 1] = '\0';
 119         msg.tsp_seq = htons((u_short)0);
 120         msg.tsp_time.tv_sec = htonl((u_long)tval);
 121         msg.tsp_time.tv_usec = htonl((u_long)0);
 122         length = sizeof(struct sockaddr_in);
 123         if (connect(s, (struct sockaddr *)&dest, length) < 0) {
 124                 warn("connect");
 125                 goto bad;
 126         }
 127         if (send(s, (char *)&msg, sizeof(struct tsp), 0) < 0) {
 128                 if (errno != ECONNREFUSED)
 129                         warn("send");
 130                 goto bad;
 131         }
 132
 133         timed_ack = -1;
 134         waittime = WAITACK;
 135 loop:
 136         tout.tv_sec = waittime;
 137         tout.tv_usec = 0;
 138
 139         FD_ZERO(&ready);
 140         FD_SET(s, &ready);
 141         found = select(FD_SETSIZE, &ready, (fd_set *)0, (fd_set *)0, &tout);
 142
 143         length = sizeof(lerr);
 144         if (!getsockopt(s,
 145             SOL_SOCKET, SO_ERROR, (char *)&lerr, &length) && lerr) {
 146                 if (lerr != ECONNREFUSED)
 147                         warnc(lerr, "send (delayed error)");
 148                 goto bad;
 149         }
 150
 151         if (found > 0 && FD_ISSET(s, &ready)) {
 152                 length = sizeof(struct sockaddr_in);
 153                 if (recvfrom(s, &msg, sizeof(struct tsp), 0,
 154                     (struct sockaddr *)&from, &length) < 0) {
 155                         if (errno != ECONNREFUSED)
 156                                 warn("recvfrom");
 157                         goto bad;
 158                 }
 159                 msg.tsp_seq = ntohs(msg.tsp_seq);
 160                 msg.tsp_time.tv_sec = ntohl(msg.tsp_time.tv_sec);
 161                 msg.tsp_time.tv_usec = ntohl(msg.tsp_time.tv_usec);
 162                 switch (msg.tsp_type) {
 163                 case TSP_ACK:
 164                         timed_ack = TSP_ACK;
 165                         waittime = WAITDATEACK;
 166                         goto loop;
 167                 case TSP_DATEACK:
 168                         (void)close(s);
 169                         return (0);
 170                 default:
 171                         warnx("wrong ack received from timed: %s",
 172                             tsptype[msg.tsp_type]);
 173                         timed_ack = -1;
 174                         break;
 175                 }
 176         }
 177         if (timed_ack == -1)
 178                 warnx("can't reach time daemon, time set locally");
 179
 180 bad:
 181         (void)close(s);
 182         return (retval = 2);
 183 }