usr.sbin/dntpd/ntpreq.c

   1 /*
   2  * Copyright (c) 2005 The DragonFly Project.  All rights reserved.
   3  *
   4  * This code is derived from software contributed to The DragonFly Project
   5  * by Matthew Dillon <dillon@backplane.com>
   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  *
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in
  15  *    the documentation and/or other materials provided with the
  16  *    distribution.
  17  * 3. Neither the name of The DragonFly Project nor the names of its
  18  *    contributors may be used to endorse or promote products derived
  19  *    from this software without specific, prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  22  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  23  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
  24  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
  25  * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
  26  * INCIDENTAL, SPECIAL, EXEMPLARY OR CONSEQUENTIAL DAMAGES (INCLUDING,
  27  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  28  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
  29  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
  30  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
  31  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  32  * SUCH DAMAGE.
  33  *
  34  * $DragonFly: src/usr.sbin/dntpd/ntpreq.c,v 1.3 2005/04/24 09:39:27 dillon Exp $
  35  */
  36
  37 #include "defs.h"
  38
  39 static __inline void
  40 s_fixedpt_ntoh(struct s_fixedpt *fixed)
  41 {
  42     fixed->int_parts = ntohs(fixed->int_parts);
  43     fixed->fractions = ntohs(fixed->fractions);
  44 }
  45
  46 static __inline void
  47 s_fixedpt_hton(struct s_fixedpt *fixed)
  48 {
  49     fixed->int_parts = htons(fixed->int_parts);
  50     fixed->fractions = htons(fixed->fractions);
  51 }
  52
  53
  54 static __inline void
  55 l_fixedpt_ntoh(struct l_fixedpt *fixed)
  56 {
  57     fixed->int_partl = ntohl(fixed->int_partl);
  58     fixed->fractionl = ntohl(fixed->fractionl);
  59 }
  60
  61 static __inline void
  62 l_fixedpt_hton(struct l_fixedpt *fixed)
  63 {
  64     fixed->int_partl = htonl(fixed->int_partl);
  65     fixed->fractionl = htonl(fixed->fractionl);
  66 }
  67
  68 static void
  69 ntp_ntoh(struct ntp_msg *msg)
  70 {
  71     msg->refid = ntohl(msg->refid);
  72     s_fixedpt_ntoh(&msg->rootdelay);
  73     s_fixedpt_ntoh(&msg->dispersion);
  74     l_fixedpt_ntoh(&msg->reftime);
  75     l_fixedpt_ntoh(&msg->orgtime);
  76     l_fixedpt_ntoh(&msg->rectime);
  77     l_fixedpt_ntoh(&msg->xmttime);
  78     msg->keyid = ntohl(msg->keyid);
  79 }
  80
  81 static void
  82 ntp_hton(struct ntp_msg *msg)
  83 {
  84     msg->refid = htonl(msg->refid);
  85     s_fixedpt_hton(&msg->rootdelay);
  86     s_fixedpt_hton(&msg->dispersion);
  87     l_fixedpt_hton(&msg->reftime);
  88     l_fixedpt_hton(&msg->orgtime);
  89     l_fixedpt_hton(&msg->rectime);
  90     l_fixedpt_hton(&msg->xmttime);
  91     msg->keyid = htonl(msg->keyid);
  92 }
  93
  94 int
  95 udp_ntptimereq(int fd, struct timeval *rtvp, struct timeval *ltvp,
  96                struct timeval *lbtvp)
  97 {
  98     struct ntp_msg wmsg;
  99     struct ntp_msg rmsg;
 100     struct timeval tv1;
 101     struct timeval seltv;
 102     fd_set rfds;
 103     int error;
 104     int n;
 105
 106     /*
 107      * Setup the message
 108      */
 109     bzero(&wmsg, sizeof(wmsg));
 110     wmsg.status = LI_ALARM | MODE_CLIENT | (NTP_VERSION << 3);
 111     wmsg.ppoll = 4;
 112     wmsg.precision = -6;
 113     wmsg.rootdelay.int_parts = 1;
 114     wmsg.dispersion.int_parts = 1;
 115     wmsg.refid = 0;
 116     wmsg.xmttime.int_partl = time(NULL) + JAN_1970;
 117     wmsg.xmttime.fractionl = random();
 118
 119     /*
 120      * Timed transmit
 121      */
 122     gettimeofday(&tv1, NULL);
 123     ntp_hton(&wmsg);
 124     n = write(fd, &wmsg, NTP_MSGSIZE_NOAUTH);
 125     if (n != NTP_MSGSIZE_NOAUTH)
 126         return(-1);
 127     ntp_ntoh(&wmsg);
 128
 129     /*
 130      * Wait for reply
 131      */
 132     seltv.tv_sec = 2;
 133     seltv.tv_usec = 0;
 134     FD_ZERO(&rfds);
 135     FD_SET(fd, &rfds);
 136     select(fd + 1, &rfds, NULL, NULL, &seltv);
 137
 138     /*
 139      * Drain socket, process the first matching reply or error out.
 140      * Errors are not necessarily fatal.  e.g. a signal could cause select()
 141      * to return early.
 142      */
 143     error = -1;
 144     while ((n = read(fd, &rmsg, sizeof(rmsg))) >= 0) {
 145         if (n < NTP_MSGSIZE_NOAUTH)
 146             continue;
 147         ntp_ntoh(&rmsg);
 148         if (bcmp(&rmsg.orgtime, &wmsg.xmttime, sizeof(rmsg.orgtime)) != 0)
 149             continue;
 150
 151         /*
 152          * Ok, we have a good reply, how long did it take?
 153          *
 154          * reftime
 155          * orgtime
 156          * rectime
 157          * xmttime
 158          */
 159         gettimeofday(ltvp, NULL);
 160         sysntp_getbasetime(lbtvp);
 161
 162         l_fixedpt_to_tv(&rmsg.xmttime, rtvp);
 163         tv_add_micro(rtvp, (long)(tv_delta_double(&tv1, ltvp) * 1000000.0) / 2);
 164
 165         error = 0;
 166         break;
 167     }
 168     return(error);
 169 }
 170