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. 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  * @(#)netdate.c        8.1 (Berkeley) 5/31/93
  30  * $FreeBSD: src/bin/date/netdate.c,v 1.18 2004/04/06 20:06:45 markm Exp $
  31  * $DragonFly: src/bin/date/netdate.c,v 1.8 2008/11/10 14:56:33 swildner Exp $
  32  */
  33
  34 #include <sys/param.h>
  35 #include <sys/time.h>
  36 #include <sys/socket.h>
  37
  38 #include <netinet/in.h>
  39 #include <netdb.h>
  40 #define TSPTYPES
  41 #include <protocols/timed.h>
  42
  43 #include <err.h>
  44 #include <errno.h>
  45 #include <string.h>
  46 #include <unistd.h>
  47
  48 #include "extern.h"
  49
  50 #define WAITACK         2       /* seconds */
  51 #define WAITDATEACK     5       /* seconds */
  52
  53 extern int retval;
  54
  55 /*
  56  * Set the date in the machines controlled by timedaemons by communicating the
  57  * new date to the local timedaemon.  If the timedaemon is in the master state,
  58  * it performs the correction on all slaves.  If it is in the slave state, it
  59  * notifies the master that a correction is needed.
  60  * Returns 0 on success.  Returns > 0 on failure, setting retval to 2;
  61  */
  62 int
  63 netsettime(time_t tval)
  64 {
  65         struct timeval tout;
  66         struct servent *sp;
  67         struct tsp msg;
  68         struct sockaddr_in tmpsin, dest, from;
  69         fd_set ready;
  70         long waittime;
  71         int s, port, timed_ack, found, errn;
  72         socklen_t length;
  73         char hostname[MAXHOSTNAMELEN];
  74
  75         if ((sp = getservbyname("timed", "udp")) == NULL) {
  76                 warnx("timed/udp: unknown service");
  77                 return (retval = 2);
  78         }
  79
  80         dest.sin_port = sp->s_port;
  81         dest.sin_family = AF_INET;
  82         dest.sin_addr.s_addr = htonl((u_long)INADDR_ANY);
  83         s = socket(AF_INET, SOCK_DGRAM, 0);
  84         if (s < 0) {
  85                 if (errno != EPROTONOSUPPORT)
  86                         warn("timed");
  87                 return (retval = 2);
  88         }
  89
  90         memset(&tmpsin, 0, sizeof(tmpsin));
  91         tmpsin.sin_family = AF_INET;
  92         for (port = IPPORT_RESERVED - 1; port > IPPORT_RESERVED / 2; port--) {
  93                 tmpsin.sin_port = htons((u_short)port);
  94                 if (bind(s, (struct sockaddr *)&tmpsin, sizeof(tmpsin)) >= 0)
  95                         break;
  96                 if (errno == EADDRINUSE)
  97                         continue;
  98                 if (errno != EADDRNOTAVAIL)
  99                         warn("bind");
 100                 goto bad;
 101         }
 102         if (port == IPPORT_RESERVED / 2) {
 103                 warnx("all ports in use");
 104                 goto bad;
 105         }
 106         msg.tsp_type = TSP_SETDATE;
 107         msg.tsp_vers = TSPVERSION;
 108         if (gethostname(hostname, sizeof(hostname))) {
 109                 warn("gethostname");
 110                 goto bad;
 111         }
 112         strncpy(msg.tsp_name, hostname, sizeof(msg.tsp_name) - 1);
 113         msg.tsp_name[sizeof(msg.tsp_name) - 1] = '\0';
 114         msg.tsp_seq = htons((u_short)0);
 115         msg.tsp_time.tv_sec = htonl((u_long)tval);
 116         msg.tsp_time.tv_usec = htonl((u_long)0);
 117         length = sizeof(struct sockaddr_in);
 118         if (connect(s, (struct sockaddr *)&dest, length) < 0) {
 119                 warn("connect");
 120                 goto bad;
 121         }
 122         if (send(s, (char *)&msg, sizeof(struct tsp), 0) < 0) {
 123                 if (errno != ECONNREFUSED)
 124                         warn("send");
 125                 goto bad;
 126         }
 127
 128         timed_ack = -1;
 129         waittime = WAITACK;
 130 loop:
 131         tout.tv_sec = waittime;
 132         tout.tv_usec = 0;
 133
 134         FD_ZERO(&ready);
 135         FD_SET(s, &ready);
 136         found = select(FD_SETSIZE, &ready, NULL, NULL, &tout);
 137
 138         length = sizeof(errn);
 139         if (!getsockopt(s,
 140             SOL_SOCKET, SO_ERROR, (char *)&errn, &length) && errn) {
 141                 if (errn != ECONNREFUSED)
 142                         warnc(errn, "send (delayed error)");
 143                 goto bad;
 144         }
 145
 146         if (found > 0 && FD_ISSET(s, &ready)) {
 147                 length = sizeof(struct sockaddr_in);
 148                 if (recvfrom(s, &msg, sizeof(struct tsp), 0,
 149                     (struct sockaddr *)&from, &length) < 0) {
 150                         if (errno != ECONNREFUSED)
 151                                 warn("recvfrom");
 152                         goto bad;
 153                 }
 154                 msg.tsp_seq = ntohs(msg.tsp_seq);
 155                 msg.tsp_time.tv_sec = ntohl(msg.tsp_time.tv_sec);
 156                 msg.tsp_time.tv_usec = ntohl(msg.tsp_time.tv_usec);
 157                 switch (msg.tsp_type) {
 158                 case TSP_ACK:
 159                         timed_ack = TSP_ACK;
 160                         waittime = WAITDATEACK;
 161                         goto loop;
 162                 case TSP_DATEACK:
 163                         close(s);
 164                         return (0);
 165                 default:
 166                         warnx("wrong ack received from timed: %s",
 167                             tsptype[msg.tsp_type]);
 168                         timed_ack = -1;
 169                         break;
 170                 }
 171         }
 172         if (timed_ack == -1)
 173                 warnx("can't reach time daemon, time set locally");
 174
 175 bad:
 176         close(s);
 177         return (retval = 2);
 178 }