mirror of
https://github.com/freebsd/freebsd-src
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2795 lines
76 KiB
C
2795 lines
76 KiB
C
/*
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* ntp_proto.c - NTP version 4 protocol machinery
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*
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* $FreeBSD$
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*/
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#ifdef HAVE_CONFIG_H
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#include <config.h>
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#endif
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#include "ntpd.h"
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#include "ntp_stdlib.h"
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#include "ntp_unixtime.h"
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#include "ntp_control.h"
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#include "ntp_string.h"
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#include "ntp_crypto.h"
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#include <stdio.h>
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#if defined(VMS) && defined(VMS_LOCALUNIT) /*wjm*/
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#include "ntp_refclock.h"
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#endif
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#if defined(__FreeBSD__) && __FreeBSD__ >= 3
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#include <sys/sysctl.h>
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#endif
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/*
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* System variables are declared here. See Section 3.2 of the
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* specification.
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*/
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u_char sys_leap; /* system leap indicator */
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u_char sys_stratum; /* stratum of system */
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s_char sys_precision; /* local clock precision */
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double sys_rootdelay; /* roundtrip delay to primary source */
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double sys_rootdispersion; /* dispersion to primary source */
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u_int32 sys_refid; /* reference source for local clock */
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static double sys_offset; /* current local clock offset */
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l_fp sys_reftime; /* time we were last updated */
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struct peer *sys_peer; /* our current peer */
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struct peer *sys_prefer; /* our cherished peer */
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#ifdef AUTOKEY
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u_long sys_automax; /* maximum session key lifetime */
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#endif /* AUTOKEY */
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/*
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* Nonspecified system state variables.
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*/
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int sys_bclient; /* we set our time to broadcasts */
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double sys_bdelay; /* broadcast client default delay */
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int sys_authenticate; /* requre authentication for config */
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l_fp sys_authdelay; /* authentication delay */
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static u_long sys_authdly[2]; /* authentication delay shift reg */
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static u_char leap_consensus; /* consensus of survivor leap bits */
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static double sys_selerr; /* select error (squares) */
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static double sys_syserr; /* system error (squares) */
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keyid_t sys_private; /* private value for session seed */
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int sys_manycastserver; /* respond to manycast client pkts */
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u_int sys_survivors; /* truest of the truechimers */
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int peer_ntpdate; /* active peers in ntpdate mode */
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#ifdef AUTOKEY
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char *sys_hostname; /* gethostname() name */
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#endif /* AUTOKEY */
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/*
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* Statistics counters
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*/
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u_long sys_stattime; /* time when we started recording */
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u_long sys_badstratum; /* packets with invalid stratum */
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u_long sys_oldversionpkt; /* old version packets received */
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u_long sys_newversionpkt; /* new version packets received */
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u_long sys_unknownversion; /* don't know version packets */
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u_long sys_badlength; /* packets with bad length */
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u_long sys_processed; /* packets processed */
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u_long sys_badauth; /* packets dropped because of auth */
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u_long sys_limitrejected; /* pkts rejected due to client count per net */
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static double root_distance P((struct peer *));
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static double clock_combine P((struct peer **, int));
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static void peer_xmit P((struct peer *));
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static void fast_xmit P((struct recvbuf *, int, keyid_t, int));
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static void clock_update P((void));
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int default_get_precision P((void));
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/*
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* transmit - Transmit Procedure. See Section 3.4.2 of the
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* specification.
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*/
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void
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transmit(
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struct peer *peer /* peer structure pointer */
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)
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{
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int hpoll;
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hpoll = peer->hpoll;
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if (peer->burst == 0) {
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u_char oreach;
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/*
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* The polling state machine. There are two kinds of
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* machines, those that never expect a reply (broadcast
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* and manycast server modes) and those that do (all
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* other modes). The dance is intricate...
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*/
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if (peer->cast_flags & (MDF_BCAST | MDF_MCAST)) {
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/*
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* In broadcast mode the poll interval is fixed
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* at minpoll and the ttl at ttlmax.
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*/
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hpoll = peer->minpoll;
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peer->ttl = peer->ttlmax;
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#ifdef AUTOKEY
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} else if (peer->cast_flags & MDF_ACAST) {
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/*
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* In manycast mode we start with the minpoll
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* interval and ttl. However, the actual poll
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* interval is eight times the nominal poll
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* interval shown here. If fewer than three
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* servers are found, the ttl is increased by
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* one and we try again. If this continues to
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* the max ttl, the poll interval is bumped by
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* one and we try again. If at least three
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* servers are found, the poll interval
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* increases with the system poll interval to
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* the max and we continue indefinately.
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* However, about once per day when the
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* agreement parameters are refreshed, the
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* manycast clients are reset and we start from
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* the beginning. This is to catch and clamp the
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* ttl to the lowest practical value and avoid
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* knocking on spurious doors.
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*/
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if (sys_survivors < NTP_MINCLOCK && peer->ttl <
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peer->ttlmax)
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peer->ttl++;
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hpoll = sys_poll;
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#endif /* AUTOKEY */
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} else {
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/*
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* For associations expecting a reply, the
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* watchdog counter is bumped by one if the peer
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* has not been heard since the previous poll.
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* If the counter reaches the max, the peer is
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* demobilized if not configured and just
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* cleared if it is, but in this case the poll
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* interval is bumped by one.
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*/
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if (peer->unreach < NTP_UNREACH) {
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peer->unreach++;
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} else if (!(peer->flags & FLAG_CONFIG)) {
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unpeer(peer);
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clock_select();
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return;
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} else {
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peer_clear(peer);
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hpoll++;
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}
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}
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oreach = peer->reach;
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peer->reach <<= 1;
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if (peer->reach == 0) {
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/*
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* If this association has become unreachable,
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* clear it and raise a trap.
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*/
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if (oreach != 0) {
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report_event(EVNT_UNREACH, peer);
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peer->timereachable = current_time;
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if (!(peer->flags & FLAG_CONFIG)) {
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unpeer(peer);
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clock_select();
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return;
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} else {
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peer_clear(peer);
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hpoll = peer->minpoll;
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}
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}
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if (peer->flags & FLAG_IBURST)
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peer->burst = NTP_SHIFT;
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} else {
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/*
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* Here the peer is reachable. If it has not
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* been heard for three consecutive polls, stuff
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* the clock filter. Next, determine the poll
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* interval. If the peer is a synchronization
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* candidate, use the system poll interval. If
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* the peer is not sane, increase it by one. If
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* the number of valid updates is not greater
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* than half the register size, clamp it to the
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* minimum. This is to quickly recover the time
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* variables when a noisy peer shows life.
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*/
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if (!(peer->reach & 0x07)) {
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clock_filter(peer, 0., 0., MAXDISPERSE);
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clock_select();
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}
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if ((peer->stratum > 1 && peer->refid ==
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peer->dstadr->sin.sin_addr.s_addr) ||
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peer->stratum >= STRATUM_UNSPEC)
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hpoll++;
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else
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hpoll = sys_poll;
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if (peer->flags & FLAG_BURST)
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peer->burst = NTP_SHIFT;
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}
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} else {
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peer->burst--;
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if (peer->burst == 0) {
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/*
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* If a broadcast client at this point, the
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* burst has concluded, so we switch to client
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* mode and purge the keylist, since no further
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* transmissions will be made.
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*/
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if (peer->cast_flags & MDF_BCLNT) {
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peer->hmode = MODE_BCLIENT;
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#ifdef AUTOKEY
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key_expire(peer);
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#endif /* AUTOKEY */
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}
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poll_update(peer, hpoll);
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clock_select();
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/*
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* If ntpdate mode and the clock has not been
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* set and all peers have completed the burst,
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* we declare a successful failure.
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*/
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if (mode_ntpdate) {
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peer_ntpdate--;
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if (peer_ntpdate > 0)
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return;
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NLOG(NLOG_SYNCEVENT | NLOG_SYSEVENT)
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msyslog(LOG_NOTICE,
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"no reply; clock not set");
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printf(
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"ntpd: no reply; clock not set\n");
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exit(0);
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}
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return;
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}
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}
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peer->outdate = current_time;
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poll_update(peer, hpoll);
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/*
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* We need to be very careful about honking uncivilized time.
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* Never transmit if in broadcast client mode or access denied.
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* If in broadcast mode, transmit only if synchronized to a
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* valid source.
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*/
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if (peer->hmode == MODE_BCLIENT || peer->flash & TEST4) {
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return;
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} else if (peer->hmode == MODE_BROADCAST) {
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if (sys_peer == NULL)
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return;
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}
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peer_xmit(peer);
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}
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/*
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* receive - Receive Procedure. See section 3.4.3 in the specification.
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*/
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void
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receive(
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struct recvbuf *rbufp
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)
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{
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register struct peer *peer;
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register struct pkt *pkt;
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int hismode;
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int oflags;
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int restrict_mask;
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int has_mac; /* length of MAC field */
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int authlen; /* offset of MAC field */
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int is_authentic; /* cryptosum ok */
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keyid_t skeyid; /* cryptographic keys */
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struct sockaddr_in *dstadr_sin; /* active runway */
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#ifdef AUTOKEY
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keyid_t pkeyid, tkeyid; /* cryptographic keys */
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#endif /* AUTOKEY */
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struct peer *peer2;
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int retcode = AM_NOMATCH;
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/*
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* Monitor the packet and get restrictions. Note that the packet
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* length for control and private mode packets must be checked
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* by the service routines. Note that no statistics counters are
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* recorded for restrict violations, since these counters are in
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* the restriction routine. Note the careful distinctions here
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* between a packet with a format error and a packet that is
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* simply discarded without prejudice. Some restrictions have to
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* be handled later in order to generate a kiss-of-death packet.
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*/
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ntp_monitor(rbufp);
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restrict_mask = restrictions(&rbufp->recv_srcadr);
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#ifdef DEBUG
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if (debug > 2)
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printf("receive: at %ld %s<-%s restrict %02x\n",
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current_time, ntoa(&rbufp->dstadr->sin),
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ntoa(&rbufp->recv_srcadr), restrict_mask);
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#endif
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if (restrict_mask & RES_IGNORE)
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return; /* no anything */
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if (!(SRCPORT(&rbufp->recv_srcadr) == NTP_PORT ||
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SRCPORT(&rbufp->recv_srcadr) >= IPPORT_RESERVED)) {
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sys_badlength++;
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return; /* invalid port */
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}
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pkt = &rbufp->recv_pkt;
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if (PKT_VERSION(pkt->li_vn_mode) == NTP_VERSION) {
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sys_newversionpkt++; /* new version */
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} else if (!(restrict_mask & RES_VERSION) &&
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PKT_VERSION(pkt->li_vn_mode) >= NTP_OLDVERSION) {
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sys_oldversionpkt++; /* old version */
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} else {
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sys_unknownversion++;
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return; /* invalid version */
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}
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if (PKT_MODE(pkt->li_vn_mode) == MODE_PRIVATE) {
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if (restrict_mask & RES_NOQUERY)
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return; /* no query private */
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process_private(rbufp, ((restrict_mask &
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RES_NOMODIFY) == 0));
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return;
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}
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if (PKT_MODE(pkt->li_vn_mode) == MODE_CONTROL) {
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if (restrict_mask & RES_NOQUERY)
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return; /* no query control */
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process_control(rbufp, restrict_mask);
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return;
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}
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if (rbufp->recv_length < LEN_PKT_NOMAC) {
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sys_badlength++;
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return; /* runt packet */
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}
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/*
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* Validate mode. Note that NTPv1 is no longer supported.
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*/
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hismode = (int)PKT_MODE(pkt->li_vn_mode);
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if (hismode == MODE_UNSPEC) {
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sys_badlength++;
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return; /* invalid mode */
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}
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/*
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* Discard broadcast packets received on the wildcard interface
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* or if not enabled as broadcast client.
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*/
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if (PKT_MODE(pkt->li_vn_mode) == MODE_BROADCAST &&
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(rbufp->dstadr == any_interface || !sys_bclient))
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return;
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/*
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* Parse the extension field if present. We figure out whether
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* an extension field is present by measuring the MAC size. If
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* the number of words following the packet header is 0 or 1, no
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* MAC is present and the packet is not authenticated. If 1, the
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* packet is a reply to a previous request that failed to
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* authenticate. If 3, the packet is authenticated with DES; if
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* 5, the packet is authenticated with MD5. If greater than 5,
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* an extension field is present. If 2 or 4, the packet is a
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* runt and goes poof! with a brilliant flash.
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*/
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skeyid = 0;
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#ifdef AUTOKEY
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pkeyid = tkeyid = 0;
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#endif /* AUTOKEY */
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authlen = LEN_PKT_NOMAC;
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while ((has_mac = rbufp->recv_length - authlen) > 0) {
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int temp;
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if (has_mac % 4 != 0 || has_mac < 0) {
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sys_badlength++;
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return;
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}
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if (has_mac == 1 * 4 || has_mac == 3 * 4 || has_mac ==
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MAX_MAC_LEN) {
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skeyid = ntohl(((u_int32 *)pkt)[authlen / 4]);
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break;
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} else if (has_mac > MAX_MAC_LEN) {
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temp = ntohl(((u_int32 *)pkt)[authlen / 4]) &
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0xffff;
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if (temp < 4 || temp % 4 != 0) {
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sys_badlength++;
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return;
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}
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authlen += temp;
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} else {
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sys_badlength++;
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return;
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}
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}
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/*
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* We have tossed out as many buggy packets as possible early in
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* the game to reduce the exposure to a clogging attack. Now we
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* have to burn some cycles to find the association and
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* authenticate the packet if required. Note that we burn only
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* MD5 or DES cycles, again to reduce exposure. There may be no
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* matching association and that's okay.
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*
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* More on the autokey mambo. Normally the local interface is
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* found when the association was mobilized with respect to a
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* designated remote address. We assume packets arriving from
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* the remote address arrive via this interface and the local
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* address used to construct the autokey is the unicast address
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* of the interface. However, if the sender is a broadcaster,
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* the interface broadcast address is used instead.
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* Notwithstanding this technobabble, if the sender is a
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* multicaster, the broadcast address is null, so we use the
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* unicast address anyway. Don't ask.
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*/
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peer = findpeer(&rbufp->recv_srcadr, rbufp->dstadr, rbufp->fd,
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hismode, &retcode);
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is_authentic = 0;
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dstadr_sin = &rbufp->dstadr->sin;
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if (has_mac == 0) {
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#ifdef DEBUG
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if (debug)
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printf("receive: at %ld %s<-%s mode %d code %d\n",
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current_time, ntoa(&rbufp->dstadr->sin),
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ntoa(&rbufp->recv_srcadr), hismode, retcode);
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#endif
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} else {
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#ifdef AUTOKEY
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/*
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* For autokey modes, generate the session key
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* and install in the key cache. Use the socket
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* broadcast or unicast address as appropriate.
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*/
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if (skeyid > NTP_MAXKEY) {
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/*
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* More on the autokey dance (AKD). A cookie is
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* constructed from public and private values.
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* For broadcast packets, the cookie is public
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* (zero). For packets that match no
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* association, the cookie is hashed from the
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* addresses and private value. For server
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* packets, the cookie was previously obtained
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* from the server. For symmetric modes, the
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* cookie was previously constructed using an
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* agreement protocol; however, should PKI be
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* unavailable, we construct a fake agreement as
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* the EXOR of the peer and host cookies.
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*
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* hismode ephemeral persistent
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* =======================================
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* active 0 cookie#
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* passive 0% cookie#
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* client sys cookie 0%
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* server 0% sys cookie
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* broadcast 0 0
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*
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* # if unsync, 0
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* % can't happen
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*/
|
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if (hismode == MODE_BROADCAST) {
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|
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/*
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* For broadcaster, use the interface
|
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* broadcast address when available;
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* otherwise, use the unicast address
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* found when the association was
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* mobilized.
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*/
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pkeyid = 0;
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if (rbufp->dstadr->bcast.sin_addr.s_addr
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!= 0)
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dstadr_sin =
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&rbufp->dstadr->bcast;
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} else if (peer == NULL) {
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pkeyid = session_key(
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&rbufp->recv_srcadr, dstadr_sin, 0,
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sys_private, 0);
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} else {
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pkeyid = peer->pcookie.key;
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}
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|
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/*
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* The session key includes both the public
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* values and cookie. In case of an extension
|
|
* field, the cookie used for authentication
|
|
* purposes is zero. Note the hash is saved for
|
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* use later in the autokey mambo.
|
|
*/
|
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if (authlen > LEN_PKT_NOMAC && pkeyid != 0) {
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session_key(&rbufp->recv_srcadr,
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dstadr_sin, skeyid, 0, 2);
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tkeyid = session_key(
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&rbufp->recv_srcadr, dstadr_sin,
|
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skeyid, pkeyid, 0);
|
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} else {
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tkeyid = session_key(
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&rbufp->recv_srcadr, dstadr_sin,
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skeyid, pkeyid, 2);
|
|
}
|
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|
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}
|
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#endif /* AUTOKEY */
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|
|
|
/*
|
|
* Compute the cryptosum. Note a clogging attack may
|
|
* succeed in bloating the key cache. If an autokey,
|
|
* purge it immediately, since we won't be needing it
|
|
* again.
|
|
*/
|
|
if (authdecrypt(skeyid, (u_int32 *)pkt, authlen,
|
|
has_mac))
|
|
is_authentic = 1;
|
|
else
|
|
sys_badauth++;
|
|
#ifdef AUTOKEY
|
|
if (skeyid > NTP_MAXKEY)
|
|
authtrust(skeyid, 0);
|
|
#endif /* AUTOKEY */
|
|
#ifdef DEBUG
|
|
if (debug)
|
|
printf(
|
|
"receive: at %ld %s<-%s mode %d code %d keyid %08x len %d mac %d auth %d\n",
|
|
current_time, ntoa(dstadr_sin),
|
|
ntoa(&rbufp->recv_srcadr), hismode, retcode,
|
|
skeyid, authlen, has_mac,
|
|
is_authentic);
|
|
#endif
|
|
}
|
|
|
|
/*
|
|
* The association matching rules are implemented by a set of
|
|
* routines and a table in ntp_peer.c. A packet matching an
|
|
* association is processed by that association. If not and
|
|
* certain conditions prevail, then an ephemeral association is
|
|
* mobilized: a broadcast packet mobilizes a broadcast client
|
|
* aassociation; a server packet mobilizes a client association;
|
|
* a symmetric active packet mobilizes a symmetric passive
|
|
* association. And, the adventure continues...
|
|
*/
|
|
switch (retcode) {
|
|
case AM_FXMIT:
|
|
|
|
/*
|
|
* This is a client mode packet not matching a known
|
|
* association. If from a manycast client we run a few
|
|
* sanity checks before deciding to send a unicast
|
|
* server response. Otherwise, it must be a client
|
|
* request, so send a server response and go home.
|
|
*/
|
|
if (sys_manycastserver && (rbufp->dstadr->flags &
|
|
INT_MULTICAST)) {
|
|
|
|
/*
|
|
* We are picky about responding to a
|
|
* manycaster. There is no reason to respond to
|
|
* a request if our time is worse than the
|
|
* manycaster. We certainly don't reply if not
|
|
* synchronized to proventic time.
|
|
*/
|
|
if (sys_peer == NULL)
|
|
return;
|
|
|
|
/*
|
|
* We don't reply if the our stratum is greater
|
|
* than the manycaster.
|
|
*/
|
|
if (PKT_TO_STRATUM(pkt->stratum) < sys_stratum)
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* Note that we don't require an authentication check
|
|
* here, since we can't set the system clock; but, we do
|
|
* set the key ID to zero to tell the caller about this.
|
|
*/
|
|
if (is_authentic)
|
|
fast_xmit(rbufp, MODE_SERVER, skeyid,
|
|
restrict_mask);
|
|
else
|
|
fast_xmit(rbufp, MODE_SERVER, 0, restrict_mask);
|
|
return;
|
|
|
|
case AM_MANYCAST:
|
|
|
|
/*
|
|
* This is a server mode packet returned in response to
|
|
* a client mode packet sent to a multicast group
|
|
* address. The originate timestamp is a good nonce to
|
|
* reliably associate the reply with what was sent. If
|
|
* there is no match, that's curious and could be an
|
|
* intruder attempting to clog, so we just ignore it.
|
|
*
|
|
* First, make sure the packet is authentic. If so and
|
|
* the manycast association is found, we mobilize a
|
|
* client mode association, copy pertinent variables
|
|
* from the manycast to the client mode association and
|
|
* wind up the spring.
|
|
*
|
|
* There is an implosion hazard at the manycast client,
|
|
* since the manycast servers send the server packet
|
|
* immediately.
|
|
*/
|
|
if ((restrict_mask & (RES_DONTSERVE | RES_LIMITED |
|
|
RES_NOPEER)) || (sys_authenticate &&
|
|
!is_authentic))
|
|
return;
|
|
|
|
peer2 = findmanycastpeer(rbufp);
|
|
if (peer2 == 0)
|
|
return;
|
|
|
|
peer = newpeer(&rbufp->recv_srcadr, rbufp->dstadr,
|
|
MODE_CLIENT, PKT_VERSION(pkt->li_vn_mode),
|
|
sys_minpoll, NTP_MAXDPOLL, FLAG_IBURST |
|
|
(peer2->flags & (FLAG_AUTHENABLE | FLAG_SKEY)),
|
|
MDF_UCAST, 0, skeyid);
|
|
if (peer == NULL)
|
|
return;
|
|
break;
|
|
|
|
case AM_NEWPASS:
|
|
|
|
/*
|
|
* This is the first packet received from a symmetric
|
|
* active peer. First, make sure the packet is
|
|
* authentic. If so, mobilize a symmetric passive
|
|
* association.
|
|
*/
|
|
if ((restrict_mask & (RES_DONTSERVE | RES_LIMITED |
|
|
RES_NOPEER)) || (sys_authenticate &&
|
|
!is_authentic)) {
|
|
fast_xmit(rbufp, MODE_PASSIVE, 0,
|
|
restrict_mask);
|
|
return;
|
|
}
|
|
peer = newpeer(&rbufp->recv_srcadr, rbufp->dstadr,
|
|
MODE_PASSIVE, PKT_VERSION(pkt->li_vn_mode),
|
|
sys_minpoll, NTP_MAXDPOLL, sys_authenticate ?
|
|
FLAG_AUTHENABLE : 0, MDF_UCAST, 0, skeyid);
|
|
if (peer == NULL)
|
|
return;
|
|
break;
|
|
|
|
case AM_NEWBCL:
|
|
|
|
/*
|
|
* This is the first packet received from a broadcast
|
|
* server. First, make sure the packet is authentic, not
|
|
* restricted and that we are a broadcast or multicast
|
|
* client. If so, mobilize a broadcast client
|
|
* association.
|
|
*/
|
|
if ((restrict_mask & (RES_DONTSERVE | RES_LIMITED |
|
|
RES_NOPEER)) || (sys_authenticate &&
|
|
!is_authentic) || !sys_bclient)
|
|
return;
|
|
|
|
peer = newpeer(&rbufp->recv_srcadr, rbufp->dstadr,
|
|
MODE_CLIENT, PKT_VERSION(pkt->li_vn_mode),
|
|
sys_minpoll, NTP_MAXDPOLL, FLAG_MCAST |
|
|
FLAG_IBURST | (sys_authenticate ?
|
|
FLAG_AUTHENABLE : 0), MDF_BCLNT, 0, skeyid);
|
|
#ifdef AUTOKEY
|
|
#ifdef PUBKEY
|
|
if (peer == NULL)
|
|
return;
|
|
if (peer->flags & FLAG_SKEY)
|
|
crypto_recv(peer, rbufp);
|
|
#endif /* PUBKEY */
|
|
#endif /* AUTOKEY */
|
|
return;
|
|
|
|
case AM_POSSBCL:
|
|
case AM_PROCPKT:
|
|
|
|
/*
|
|
* Happiness and nothing broke. Earn some revenue.
|
|
*/
|
|
break;
|
|
|
|
default:
|
|
|
|
/*
|
|
* Invalid mode combination. Leave the island
|
|
* immediately.
|
|
*/
|
|
#ifdef DEBUG
|
|
if (debug)
|
|
printf("receive: bad protocol %d\n", retcode);
|
|
#endif
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* If the peer isn't configured, set his authenable and autokey
|
|
* status based on the packet. Once the status is set, it can't
|
|
* be unset. It seems like a silly idea to do this here, rather
|
|
* in the configuration routine, but in some goofy cases the
|
|
* first packet sent cannot be authenticated and we need a way
|
|
* for the dude to change his mind.
|
|
*/
|
|
oflags = peer->flags;
|
|
peer->timereceived = current_time;
|
|
peer->received++;
|
|
if (!(peer->flags & FLAG_CONFIG) && has_mac) {
|
|
peer->flags |= FLAG_AUTHENABLE;
|
|
#ifdef AUTOKEY
|
|
if (skeyid > NTP_MAXKEY)
|
|
peer->flags |= FLAG_SKEY;
|
|
#endif /* AUTOKEY */
|
|
}
|
|
|
|
/*
|
|
* A valid packet must be from an authentic and allowed source.
|
|
* All packets must pass the authentication allowed tests.
|
|
* Autokey authenticated packets must pass additional tests and
|
|
* public-key authenticated packets must have the credentials
|
|
* verified. If all tests are passed, the packet is forwarded
|
|
* for processing. If not, the packet is discarded and the
|
|
* association demobilized if appropriate.
|
|
*/
|
|
peer->flash = 0;
|
|
if (is_authentic) {
|
|
peer->flags |= FLAG_AUTHENTIC;
|
|
} else {
|
|
peer->flags &= ~FLAG_AUTHENTIC;
|
|
}
|
|
if (peer->hmode == MODE_BROADCAST &&
|
|
(restrict_mask & RES_DONTTRUST)) /* test 4 */
|
|
peer->flash |= TEST4; /* access denied */
|
|
if (peer->flags & FLAG_AUTHENABLE) {
|
|
if (!(peer->flags & FLAG_AUTHENTIC)) /* test 5 */
|
|
peer->flash |= TEST5; /* auth failed */
|
|
else if (!(oflags & FLAG_AUTHENABLE))
|
|
report_event(EVNT_PEERAUTH, peer);
|
|
}
|
|
if (peer->flash) {
|
|
#ifdef DEBUG
|
|
if (debug)
|
|
printf("receive: bad auth %03x\n", peer->flash);
|
|
#endif
|
|
return;
|
|
}
|
|
|
|
#ifdef AUTOKEY
|
|
/*
|
|
* More autokey dance. The rules of the cha-cha are as follows:
|
|
*
|
|
* 1. If there is no key or the key is not auto, do nothing.
|
|
*
|
|
* 2. If an extension field contains a verified signature, it is
|
|
* self-authenticated and we sit the dance.
|
|
*
|
|
* 3. If this is a server reply, check only to see that the
|
|
* transmitted key ID matches the received key ID.
|
|
*
|
|
* 4. Check to see that one or more hashes of the current key ID
|
|
* matches the previous key ID or ultimate original key ID
|
|
* obtained from the broadcaster or symmetric peer. If no
|
|
* match, sit the dance and wait for timeout.
|
|
*/
|
|
if (peer->flags & FLAG_SKEY) {
|
|
peer->flash |= TEST10;
|
|
crypto_recv(peer, rbufp);
|
|
poll_update(peer, peer->hpoll);
|
|
if (hismode == MODE_SERVER) {
|
|
if (skeyid == peer->keyid)
|
|
peer->flash &= ~TEST10;
|
|
} else if (!peer->flash & TEST10) {
|
|
peer->pkeyid = skeyid;
|
|
} else {
|
|
int i;
|
|
|
|
for (i = 0; ; i++) {
|
|
if (tkeyid == peer->pkeyid ||
|
|
tkeyid == peer->recauto.key) {
|
|
peer->flash &= ~TEST10;
|
|
peer->pkeyid = skeyid;
|
|
break;
|
|
}
|
|
if (i > peer->recauto.seq)
|
|
break;
|
|
tkeyid = session_key(
|
|
&rbufp->recv_srcadr, dstadr_sin,
|
|
tkeyid, pkeyid, 0);
|
|
}
|
|
}
|
|
#ifdef PUBKEY
|
|
|
|
/*
|
|
* This is delicious. Ordinarily, we kick out all errors
|
|
* at this point; however, in symmetric mode and just
|
|
* warming up, an unsynchronized peer must inject the
|
|
* timestamps, even if it fails further up the road. So,
|
|
* let the dude by here, but only if the jerk is not yet
|
|
* reachable. After that, he's on his own.
|
|
*/
|
|
if (!(peer->flags & FLAG_PROVEN))
|
|
peer->flash |= TEST11;
|
|
if (peer->flash && peer->reach) {
|
|
#ifdef DEBUG
|
|
if (debug)
|
|
printf("packet: bad autokey %03x\n",
|
|
peer->flash);
|
|
#endif
|
|
return;
|
|
}
|
|
#endif /* PUBKEY */
|
|
}
|
|
#endif /* AUTOKEY */
|
|
|
|
/*
|
|
* We have survived the gaunt. Forward to the packet routine. If
|
|
* a symmetric passive association has been mobilized and the
|
|
* association doesn't deserve to live, it will die in the
|
|
* transmit routine if not reachable after timeout.
|
|
*/
|
|
process_packet(peer, pkt, &rbufp->recv_time);
|
|
}
|
|
|
|
|
|
/*
|
|
* process_packet - Packet Procedure, a la Section 3.4.4 of the
|
|
* specification. Or almost, at least. If we're in here we have a
|
|
* reasonable expectation that we will be having a long term
|
|
* relationship with this host.
|
|
*/
|
|
void
|
|
process_packet(
|
|
register struct peer *peer,
|
|
register struct pkt *pkt,
|
|
l_fp *recv_ts
|
|
)
|
|
{
|
|
l_fp t10, t23;
|
|
double p_offset, p_del, p_disp;
|
|
double dtemp;
|
|
l_fp p_rec, p_xmt, p_org, p_reftime;
|
|
l_fp ci;
|
|
int pmode, pleap, pstratum;
|
|
|
|
/*
|
|
* Swap header fields and keep the books. The books amount to
|
|
* the receive timestamp and poll interval in the header. We
|
|
* need these even if there are other problems in order to crank
|
|
* up the state machine.
|
|
*/
|
|
sys_processed++;
|
|
peer->processed++;
|
|
p_del = FPTOD(NTOHS_FP(pkt->rootdelay));
|
|
p_disp = FPTOD(NTOHS_FP(pkt->rootdispersion));
|
|
NTOHL_FP(&pkt->reftime, &p_reftime);
|
|
NTOHL_FP(&pkt->rec, &p_rec);
|
|
NTOHL_FP(&pkt->xmt, &p_xmt);
|
|
if (PKT_MODE(pkt->li_vn_mode) != MODE_BROADCAST)
|
|
NTOHL_FP(&pkt->org, &p_org);
|
|
else
|
|
p_org = peer->rec;
|
|
|
|
/*
|
|
* Test for old, duplicate or unsynch packets (tests 1-3).
|
|
*/
|
|
peer->rec = *recv_ts;
|
|
pmode = PKT_MODE(pkt->li_vn_mode);
|
|
pleap = PKT_LEAP(pkt->li_vn_mode);
|
|
pstratum = PKT_TO_STRATUM(pkt->stratum);
|
|
if (L_ISHIS(&peer->org, &p_xmt)) /* count old packets */
|
|
peer->oldpkt++;
|
|
if (L_ISEQU(&peer->org, &p_xmt)) /* 1 */
|
|
peer->flash |= TEST1; /* dupe */
|
|
if (pmode != MODE_BROADCAST) {
|
|
if (!L_ISEQU(&peer->xmt, &p_org)) /* 2 */
|
|
peer->flash |= TEST2; /* bogus */
|
|
if (L_ISZERO(&p_rec) || L_ISZERO(&p_org)) /* test 3 */
|
|
peer->flash |= TEST3; /* unsynch */
|
|
}
|
|
if (L_ISZERO(&p_xmt)) /* 3 */
|
|
peer->flash |= TEST3; /* unsynch */
|
|
peer->org = p_xmt;
|
|
|
|
/*
|
|
* If tests 1-3 fail, the packet is discarded leaving only the
|
|
* receive and origin timestamps and poll interval, which is
|
|
* enough to get the protocol started.
|
|
*/
|
|
if (peer->flash) {
|
|
#ifdef DEBUG
|
|
if (debug)
|
|
printf("packet: bad data %03x\n",
|
|
peer->flash);
|
|
#endif
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* A kiss-of-death (kod) packet is returned by a server in case
|
|
* the client is denied access. It consists of the client
|
|
* request packet with the leap bits indicating never
|
|
* synchronized, stratum zero and reference ID field the ASCII
|
|
* string "DENY". If the packet originate timestamp matches the
|
|
* association transmit timestamp the kod is legitimate. If the
|
|
* peer leap bits indicate never synchronized, this must be
|
|
* access deny and the association is disabled; otherwise this
|
|
* must be a limit reject. In either case a naughty message is
|
|
* forced to the system log.
|
|
*/
|
|
if (pleap == LEAP_NOTINSYNC && pstratum >= STRATUM_UNSPEC &&
|
|
memcmp(&pkt->refid, "DENY", 4) == 0) {
|
|
if (peer->leap == LEAP_NOTINSYNC) {
|
|
peer->stratum = STRATUM_UNSPEC;
|
|
peer->flash |= TEST4;
|
|
memcpy(&peer->refid, &pkt->refid, 4);
|
|
msyslog(LOG_INFO, "access denied");
|
|
} else {
|
|
msyslog(LOG_INFO, "limit reject");
|
|
}
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* Test for valid peer data (tests 6-8)
|
|
*/
|
|
ci = p_xmt;
|
|
L_SUB(&ci, &p_reftime);
|
|
LFPTOD(&ci, dtemp);
|
|
if (pleap == LEAP_NOTINSYNC || /* 6 */
|
|
pstratum >= STRATUM_UNSPEC || dtemp < 0)
|
|
peer->flash |= TEST6; /* bad synch */
|
|
if (!(peer->flags & FLAG_CONFIG) && sys_peer != NULL) { /* 7 */
|
|
if (pstratum > sys_stratum && pmode != MODE_ACTIVE) {
|
|
peer->flash |= TEST7; /* bad stratum */
|
|
sys_badstratum++;
|
|
}
|
|
}
|
|
if (p_del < 0 || p_disp < 0 || p_del / /* 8 */
|
|
2 + p_disp >= MAXDISPERSE)
|
|
peer->flash |= TEST8; /* bad peer distance */
|
|
if (peer->flash) {
|
|
#ifdef DEBUG
|
|
if (debug)
|
|
printf("packet: bad header %03x\n",
|
|
peer->flash);
|
|
#endif
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* The header is valid. Capture the remaining header values and
|
|
* mark as reachable.
|
|
*/
|
|
record_raw_stats(&peer->srcadr, &peer->dstadr->sin, &p_org,
|
|
&p_rec, &p_xmt, &peer->rec);
|
|
peer->leap = pleap;
|
|
peer->pmode = pmode;
|
|
peer->stratum = pstratum;
|
|
peer->ppoll = pkt->ppoll;
|
|
peer->precision = pkt->precision;
|
|
peer->rootdelay = p_del;
|
|
peer->rootdispersion = p_disp;
|
|
peer->refid = pkt->refid;
|
|
peer->reftime = p_reftime;
|
|
if (!(peer->reach)) {
|
|
report_event(EVNT_REACH, peer);
|
|
peer->timereachable = current_time;
|
|
}
|
|
peer->reach |= 1;
|
|
peer->unreach = 0;
|
|
poll_update(peer, peer->hpoll);
|
|
|
|
/*
|
|
* If running in a client/server association, calculate the
|
|
* clock offset c, roundtrip delay d and dispersion e. We use
|
|
* the equations (reordered from those in the spec). Note that,
|
|
* in a broadcast association, org has been set to the time of
|
|
* last reception. Note the computation of dispersion includes
|
|
* the system precision plus that due to the frequency error
|
|
* since the originate time.
|
|
*
|
|
* c = ((t2 - t3) + (t1 - t0)) / 2
|
|
* d = (t2 - t3) - (t1 - t0)
|
|
* e = (org - rec) (seconds only)
|
|
*/
|
|
t10 = p_xmt; /* compute t1 - t0 */
|
|
L_SUB(&t10, &peer->rec);
|
|
t23 = p_rec; /* compute t2 - t3 */
|
|
L_SUB(&t23, &p_org);
|
|
ci = t10;
|
|
p_disp = clock_phi * (peer->rec.l_ui - p_org.l_ui);
|
|
|
|
/*
|
|
* If running in a broadcast association, the clock offset is
|
|
* (t1 - t0) corrected by the one-way delay, but we can't
|
|
* measure that directly. Therefore, we start up in MODE_CLIENT
|
|
* mode, set FLAG_MCAST and exchange eight messages to determine
|
|
* the clock offset. When the last message is sent, we switch to
|
|
* MODE_BCLIENT mode. The next broadcast message after that
|
|
* computes the broadcast offset and clears FLAG_MCAST.
|
|
*/
|
|
if (pmode == MODE_BROADCAST) {
|
|
if (peer->flags & FLAG_MCAST) {
|
|
LFPTOD(&ci, p_offset);
|
|
peer->estbdelay = peer->offset - p_offset;
|
|
if (peer->hmode == MODE_CLIENT)
|
|
return;
|
|
|
|
peer->flags &= ~FLAG_MCAST;
|
|
}
|
|
DTOLFP(peer->estbdelay, &t10);
|
|
L_ADD(&ci, &t10);
|
|
p_del = peer->delay;
|
|
} else {
|
|
L_ADD(&ci, &t23);
|
|
L_RSHIFT(&ci);
|
|
L_SUB(&t23, &t10);
|
|
LFPTOD(&t23, p_del);
|
|
}
|
|
p_del = max(p_del, LOGTOD(sys_precision));
|
|
LFPTOD(&ci, p_offset);
|
|
if ((peer->rootdelay + p_del) / 2. + peer->rootdispersion +
|
|
p_disp >= MAXDISPERSE) /* 9 */
|
|
peer->flash |= TEST9; /* bad peer distance */
|
|
|
|
/*
|
|
* If any flasher bits remain set at this point, abandon ship.
|
|
* Otherwise, forward to the clock filter.
|
|
*/
|
|
if (peer->flash) {
|
|
#ifdef DEBUG
|
|
if (debug)
|
|
printf("packet: bad packet data %03x\n",
|
|
peer->flash);
|
|
#endif
|
|
return;
|
|
}
|
|
clock_filter(peer, p_offset, p_del, p_disp);
|
|
clock_select();
|
|
record_peer_stats(&peer->srcadr, ctlpeerstatus(peer),
|
|
peer->offset, peer->delay, peer->disp,
|
|
SQRT(peer->jitter));
|
|
}
|
|
|
|
|
|
/*
|
|
* clock_update - Called at system process update intervals.
|
|
*/
|
|
static void
|
|
clock_update(void)
|
|
{
|
|
u_char oleap;
|
|
u_char ostratum;
|
|
|
|
/*
|
|
* Reset/adjust the system clock. Do this only if there is a
|
|
* system peer and we haven't seen that peer lately. Watch for
|
|
* timewarps here.
|
|
*/
|
|
if (sys_peer == NULL)
|
|
return;
|
|
if (sys_peer->pollsw == FALSE || sys_peer->burst > 0)
|
|
return;
|
|
sys_peer->pollsw = FALSE;
|
|
#ifdef DEBUG
|
|
if (debug)
|
|
printf("clock_update: at %ld assoc %d \n", current_time,
|
|
peer_associations);
|
|
#endif
|
|
oleap = sys_leap;
|
|
ostratum = sys_stratum;
|
|
switch (local_clock(sys_peer, sys_offset, sys_syserr)) {
|
|
|
|
/*
|
|
* Clock is too screwed up. Just exit for now.
|
|
*/
|
|
case -1:
|
|
report_event(EVNT_SYSFAULT, (struct peer *)0);
|
|
exit(1);
|
|
/*NOTREACHED*/
|
|
|
|
/*
|
|
* Clock was stepped. Flush all time values of all peers.
|
|
*/
|
|
case 1:
|
|
clear_all();
|
|
sys_peer = NULL;
|
|
sys_stratum = STRATUM_UNSPEC;
|
|
sys_poll = NTP_MINPOLL;
|
|
NLOG(NLOG_SYNCSTATUS)
|
|
msyslog(LOG_INFO, "synchronisation lost");
|
|
report_event(EVNT_CLOCKRESET, (struct peer *)0);
|
|
break;
|
|
|
|
/*
|
|
* Update the system stratum, leap bits, root delay, root
|
|
* dispersion, reference ID and reference time. We also update
|
|
* select dispersion and max frequency error. If the leap
|
|
* changes, we gotta reroll the keys.
|
|
*/
|
|
default:
|
|
sys_stratum = sys_peer->stratum + 1;
|
|
if (sys_stratum == 1)
|
|
sys_refid = sys_peer->refid;
|
|
else
|
|
sys_refid = sys_peer->srcadr.sin_addr.s_addr;
|
|
sys_reftime = sys_peer->rec;
|
|
sys_rootdelay = sys_peer->rootdelay + sys_peer->delay;
|
|
sys_leap = leap_consensus;
|
|
}
|
|
if (oleap == LEAP_NOTINSYNC) {
|
|
report_event(EVNT_SYNCCHG, (struct peer *)0);
|
|
#ifdef AUTOKEY
|
|
expire_all();
|
|
#endif /* AUTOKEY */
|
|
}
|
|
if (ostratum != sys_stratum)
|
|
report_event(EVNT_PEERSTCHG, (struct peer *)0);
|
|
}
|
|
|
|
|
|
/*
|
|
* poll_update - update peer poll interval
|
|
*/
|
|
void
|
|
poll_update(
|
|
struct peer *peer,
|
|
int hpoll
|
|
)
|
|
{
|
|
#ifdef AUTOKEY
|
|
int oldpoll;
|
|
#endif /* AUTOKEY */
|
|
|
|
/*
|
|
* A little foxtrot to determine what controls the poll
|
|
* interval. If the peer is reachable, but the last four polls
|
|
* have not been answered, use the minimum. If declared
|
|
* truechimer, use the system poll interval. This allows each
|
|
* association to ramp up the poll interval for useless sources
|
|
* and to clamp it to the minimum when first starting up.
|
|
*/
|
|
#ifdef AUTOKEY
|
|
oldpoll = peer->kpoll;
|
|
#endif /* AUTOKEY */
|
|
if (hpoll > peer->maxpoll)
|
|
peer->hpoll = peer->maxpoll;
|
|
else if (hpoll < peer->minpoll)
|
|
peer->hpoll = peer->minpoll;
|
|
else
|
|
peer->hpoll = hpoll;
|
|
|
|
/*
|
|
* Bit of adventure here. If during a burst and not timeout,
|
|
* just slink away. If timeout, figure what the next timeout
|
|
* should be. If IBURST or a reference clock, use one second. If
|
|
* not and the dude was reachable during the previous poll
|
|
* interval, randomize over 1-4 seconds; otherwise, randomize
|
|
* over 15-18 seconds. This is to give time for a modem to
|
|
* complete the call, for example. If not during a burst,
|
|
* randomize over the poll interval -1 to +2 seconds.
|
|
*
|
|
* In case of manycast server, make the poll interval, which is
|
|
* axtually the manycast beacon interval, eight times the system
|
|
* poll interval. Normally when the host poll interval settles
|
|
* up to 17.1 s, the beacon interval settles up to 2.3 hours.
|
|
*/
|
|
if (peer->burst > 0) {
|
|
if (peer->nextdate != current_time)
|
|
return;
|
|
#ifdef REFCLOCK
|
|
else if (peer->flags & FLAG_REFCLOCK)
|
|
peer->nextdate++;
|
|
#endif
|
|
else if (peer->reach & 0x1)
|
|
peer->nextdate += RANDPOLL(BURST_INTERVAL2);
|
|
else
|
|
peer->nextdate += RANDPOLL(BURST_INTERVAL1);
|
|
} else if (peer->cast_flags & MDF_ACAST) {
|
|
if (sys_survivors < NTP_MINCLOCK)
|
|
peer->kpoll = peer->hpoll;
|
|
else
|
|
peer->kpoll = peer->hpoll + 3;
|
|
peer->nextdate = peer->outdate + RANDPOLL(peer->kpoll);
|
|
} else {
|
|
peer->kpoll = max(min(peer->ppoll, peer->hpoll),
|
|
peer->minpoll);
|
|
peer->nextdate = peer->outdate + RANDPOLL(peer->kpoll);
|
|
}
|
|
if (peer->nextdate < current_time)
|
|
peer->nextdate = current_time;
|
|
#ifdef AUTOKEY
|
|
/*
|
|
* Bit of crass arrogance at this point. If the poll interval
|
|
* has changed and we have a keylist, the lifetimes in the
|
|
* keylist are probably bogus. In this case purge the keylist
|
|
* and regenerate it later.
|
|
*/
|
|
if (peer->kpoll != oldpoll)
|
|
key_expire(peer);
|
|
#endif /* AUTOKEY */
|
|
#ifdef DEBUG
|
|
if (debug > 1)
|
|
printf("poll_update: at %lu %s flags %04x poll %d burst %d last %lu next %lu\n",
|
|
current_time, ntoa(&peer->srcadr), peer->flags,
|
|
peer->kpoll, peer->burst, peer->outdate,
|
|
peer->nextdate);
|
|
#endif
|
|
}
|
|
|
|
|
|
/*
|
|
* clear - clear peer filter registers. See Section 3.4.8 of the spec.
|
|
*/
|
|
void
|
|
peer_clear(
|
|
register struct peer *peer
|
|
)
|
|
{
|
|
register int i;
|
|
u_long u_rand;
|
|
|
|
/*
|
|
* If cryptographic credentials have been acquired, toss them to
|
|
* Valhalla. Note that autokeys are ephemeral, in that they are
|
|
* tossed immediately upon use. Therefore, the keylist can be
|
|
* purged anytime without needing to preserve random keys. Note
|
|
* that, if the peer is purged, the cryptographic variables are
|
|
* purged, too. This makes it much harder to sneak in some
|
|
* unauthenticated data in the clock filter.
|
|
*/
|
|
#ifdef DEBUG
|
|
if (debug)
|
|
printf("peer_clear: at %ld assoc ID %d\n", current_time,
|
|
peer->associd);
|
|
#endif
|
|
#ifdef AUTOKEY
|
|
key_expire(peer);
|
|
#ifdef PUBKEY
|
|
if (peer->keystr != NULL)
|
|
free(peer->keystr);
|
|
if (peer->pubkey.ptr != NULL)
|
|
free(peer->pubkey.ptr);
|
|
if (peer->certif.ptr != NULL)
|
|
free(peer->certif.ptr);
|
|
#endif /* PUBKEY */
|
|
#endif /* AUTOKEY */
|
|
memset(CLEAR_TO_ZERO(peer), 0, LEN_CLEAR_TO_ZERO);
|
|
|
|
/*
|
|
* If he dies as a broadcast client, he comes back to life as
|
|
* a broadcast client in client mode in order to recover the
|
|
* initial autokey values. Note that there is no need to call
|
|
* clock_select(), since the perp has already been voted off
|
|
* the island at this point.
|
|
*/
|
|
if (peer->cast_flags & MDF_BCLNT) {
|
|
peer->flags |= FLAG_MCAST;
|
|
peer->hmode = MODE_CLIENT;
|
|
}
|
|
peer->flags &= ~(FLAG_AUTOKEY | FLAG_ASSOC);
|
|
peer->estbdelay = sys_bdelay;
|
|
peer->hpoll = peer->kpoll = peer->minpoll;
|
|
peer->ppoll = peer->maxpoll;
|
|
peer->pollsw = FALSE;
|
|
peer->jitter = MAXDISPERSE;
|
|
peer->epoch = current_time;
|
|
#ifdef REFCLOCK
|
|
if (!(peer->flags & FLAG_REFCLOCK)) {
|
|
peer->leap = LEAP_NOTINSYNC;
|
|
peer->stratum = STRATUM_UNSPEC;
|
|
}
|
|
#endif
|
|
for (i = 0; i < NTP_SHIFT; i++) {
|
|
peer->filter_order[i] = i;
|
|
peer->filter_disp[i] = MAXDISPERSE;
|
|
peer->filter_epoch[i] = current_time;
|
|
}
|
|
|
|
/*
|
|
* Randomize the first poll over 1-16s to avoid bunching.
|
|
*/
|
|
peer->update = peer->outdate = current_time;
|
|
u_rand = RANDOM;
|
|
peer->nextdate = current_time + (u_rand & ((1 <<
|
|
BURST_INTERVAL1) - 1)) + 1;
|
|
}
|
|
|
|
|
|
/*
|
|
* clock_filter - add incoming clock sample to filter register and run
|
|
* the filter procedure to find the best sample.
|
|
*/
|
|
void
|
|
clock_filter(
|
|
register struct peer *peer, /* peer structure pointer */
|
|
double sample_offset, /* clock offset */
|
|
double sample_delay, /* roundtrip delay */
|
|
double sample_disp /* dispersion */
|
|
)
|
|
{
|
|
double dst[NTP_SHIFT]; /* distance vector */
|
|
int ord[NTP_SHIFT]; /* index vector */
|
|
register int i, j, k, m;
|
|
double dsp, jit, dtemp, etemp;
|
|
|
|
/*
|
|
* Shift the new sample into the register and discard the oldest
|
|
* one. The new offset and delay come directly from the
|
|
* timestamp calculations. The dispersion grows from the last
|
|
* outbound packet or reference clock update to the present time
|
|
* and increased by the sum of the peer precision and the system
|
|
* precision. The delay can sometimes swing negative due to
|
|
* frequency skew, so it is clamped non-negative.
|
|
*/
|
|
dsp = min(LOGTOD(peer->precision) + LOGTOD(sys_precision) +
|
|
sample_disp, MAXDISPERSE);
|
|
j = peer->filter_nextpt;
|
|
peer->filter_offset[j] = sample_offset;
|
|
peer->filter_delay[j] = max(0, sample_delay);
|
|
peer->filter_disp[j] = dsp;
|
|
peer->filter_epoch[j] = current_time;
|
|
j++; j %=NTP_SHIFT;
|
|
peer->filter_nextpt = j;
|
|
|
|
/*
|
|
* Update dispersions since the last update and at the same
|
|
* time initialize the distance and index lists. The distance
|
|
* list uses a compound metric. If the sample is valid and
|
|
* younger than the minimum Allan intercept, use delay;
|
|
* otherwise, use biased dispersion.
|
|
*/
|
|
dtemp = clock_phi * (current_time - peer->update);
|
|
peer->update = current_time;
|
|
for (i = NTP_SHIFT - 1; i >= 0; i--) {
|
|
if (i != 0) {
|
|
peer->filter_disp[j] += dtemp;
|
|
if (peer->filter_disp[j] > MAXDISPERSE)
|
|
peer->filter_disp[j] = MAXDISPERSE;
|
|
}
|
|
if (peer->filter_disp[j] >= MAXDISPERSE)
|
|
dst[i] = MAXDISPERSE;
|
|
else if (peer->update - peer->filter_epoch[j] >
|
|
allan_xpt)
|
|
dst[i] = MAXDISTANCE + peer->filter_disp[j];
|
|
else
|
|
dst[i] = peer->filter_delay[j];
|
|
ord[i] = j;
|
|
j++; j %= NTP_SHIFT;
|
|
}
|
|
|
|
/*
|
|
* Sort the samples in both lists by distance.
|
|
*/
|
|
for (i = 1; i < NTP_SHIFT; i++) {
|
|
for (j = 0; j < i; j++) {
|
|
if (dst[j] > dst[i]) {
|
|
k = ord[j];
|
|
ord[j] = ord[i];
|
|
ord[i] = k;
|
|
etemp = dst[j];
|
|
dst[j] = dst[i];
|
|
dst[i] = etemp;
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Copy the index list to the association structure so ntpq
|
|
* can see it later. Prune the distance list to samples less
|
|
* than MAXDISTANCE, but keep at least two valid samples for
|
|
* jitter calculation.
|
|
*/
|
|
m = 0;
|
|
for (i = 0; i < NTP_SHIFT; i++) {
|
|
peer->filter_order[i] = ord[i];
|
|
if (dst[i] >= MAXDISPERSE || (m >= 2 && dst[i] >=
|
|
MAXDISTANCE))
|
|
continue;
|
|
m++;
|
|
}
|
|
|
|
/*
|
|
* Compute the dispersion and jitter squares. The dispersion
|
|
* is weighted exponentially by NTP_FWEIGHT (0.5) so it is
|
|
* normalized close to 1.0. The jitter is the mean of the square
|
|
* differences relative to the lowest delay sample. If no
|
|
* acceptable samples remain in the shift register, quietly
|
|
* tiptoe home leaving only the
|
|
* dispersion.
|
|
*/
|
|
jit = 0;
|
|
peer->disp = 0;
|
|
k = ord[0];
|
|
for (i = NTP_SHIFT - 1; i >= 0; i--) {
|
|
|
|
j = ord[i];
|
|
peer->disp = NTP_FWEIGHT * (peer->disp +
|
|
peer->filter_disp[j]);
|
|
if (i < m)
|
|
jit += DIFF(peer->filter_offset[j],
|
|
peer->filter_offset[k]);
|
|
}
|
|
|
|
/*
|
|
* If no acceptable samples remain in the shift register,
|
|
* quietly tiptoe home leaving only the dispersion. Otherwise,
|
|
* save the offset, delay and jitter average. Note the jitter
|
|
* must not be less than the system precision.
|
|
*/
|
|
if (m == 0)
|
|
return;
|
|
etemp = peer->offset;
|
|
peer->offset = peer->filter_offset[k];
|
|
peer->delay = peer->filter_delay[k];
|
|
if (m > 1)
|
|
jit /= m - 1;
|
|
peer->jitter = max(jit, SQUARE(LOGTOD(sys_precision)));
|
|
|
|
/*
|
|
* A new sample is useful only if it is younger than the last
|
|
* one used.
|
|
*/
|
|
if (peer->filter_epoch[k] <= peer->epoch) {
|
|
#ifdef DEBUG
|
|
if (debug)
|
|
printf("clock_filter: discard %lu\n",
|
|
peer->epoch - peer->filter_epoch[k]);
|
|
#endif
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* If the difference between the last offset and the current one
|
|
* exceeds the jitter by CLOCK_SGATE (4) and the interval since
|
|
* the last update is less than twice the system poll interval,
|
|
* consider the update a popcorn spike and ignore it.
|
|
*/
|
|
if (m > 1 && fabs(peer->offset - etemp) > SQRT(peer->jitter) *
|
|
CLOCK_SGATE && peer->filter_epoch[k] - peer->epoch <
|
|
(1 << (sys_poll + 1))) {
|
|
#ifdef DEBUG
|
|
if (debug)
|
|
printf("clock_filter: n %d popcorn spike %.6f jitter %.6f\n",
|
|
m, peer->offset, SQRT(peer->jitter));
|
|
#endif
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* The mitigated sample statistics are saved for later
|
|
* processing, but can be processed only once.
|
|
*/
|
|
peer->epoch = peer->filter_epoch[k];
|
|
peer->pollsw = TRUE;
|
|
#ifdef DEBUG
|
|
if (debug)
|
|
printf(
|
|
"clock_filter: n %d off %.6f del %.6f dsp %.6f jit %.6f, age %lu\n",
|
|
m, peer->offset, peer->delay, peer->disp,
|
|
SQRT(peer->jitter), peer->update - peer->epoch);
|
|
#endif
|
|
}
|
|
|
|
|
|
/*
|
|
* clock_select - find the pick-of-the-litter clock
|
|
*/
|
|
void
|
|
clock_select(void)
|
|
{
|
|
register struct peer *peer;
|
|
int i, j, k, n;
|
|
int nreach, nlist, nl3;
|
|
double d, e, f;
|
|
int allow, found, sw;
|
|
double high, low;
|
|
double synch[NTP_MAXCLOCK], error[NTP_MAXCLOCK];
|
|
struct peer *osys_peer;
|
|
struct peer *typeacts = NULL;
|
|
struct peer *typelocal = NULL;
|
|
struct peer *typepps = NULL;
|
|
struct peer *typesystem = NULL;
|
|
|
|
static int list_alloc = 0;
|
|
static struct endpoint *endpoint = NULL;
|
|
static int *indx = NULL;
|
|
static struct peer **peer_list = NULL;
|
|
static u_int endpoint_size = 0;
|
|
static u_int indx_size = 0;
|
|
static u_int peer_list_size = 0;
|
|
|
|
/*
|
|
* Initialize and create endpoint, index and peer lists big
|
|
* enough to handle all associations.
|
|
*/
|
|
osys_peer = sys_peer;
|
|
sys_peer = NULL;
|
|
sys_prefer = NULL;
|
|
nreach = nlist = 0;
|
|
low = 1e9;
|
|
high = -1e9;
|
|
for (n = 0; n < HASH_SIZE; n++)
|
|
nlist += peer_hash_count[n];
|
|
if (nlist > list_alloc) {
|
|
if (list_alloc > 0) {
|
|
free(endpoint);
|
|
free(indx);
|
|
free(peer_list);
|
|
}
|
|
while (list_alloc < nlist) {
|
|
list_alloc += 5;
|
|
endpoint_size += 5 * 3 * sizeof(*endpoint);
|
|
indx_size += 5 * 3 * sizeof(*indx);
|
|
peer_list_size += 5 * sizeof(*peer_list);
|
|
}
|
|
endpoint = (struct endpoint *)emalloc(endpoint_size);
|
|
indx = (int *)emalloc(indx_size);
|
|
peer_list = (struct peer **)emalloc(peer_list_size);
|
|
}
|
|
|
|
/*
|
|
* Initially, we populate the island with all the rifraff peers
|
|
* that happen to be lying around. Those with seriously
|
|
* defective clocks are immediately booted off the island. Then,
|
|
* the falsetickers are culled and put to sea. The truechimers
|
|
* remaining are subject to repeated rounds where the most
|
|
* unpopular at each round is kicked off. When the population
|
|
* has dwindled to NTP_MINCLOCK (3), the survivors split a
|
|
* million bucks and collectively crank the chimes.
|
|
*/
|
|
nlist = nl3 = 0; /* none yet */
|
|
for (n = 0; n < HASH_SIZE; n++) {
|
|
for (peer = peer_hash[n]; peer != NULL; peer =
|
|
peer->next) {
|
|
peer->flags &= ~FLAG_SYSPEER;
|
|
peer->status = CTL_PST_SEL_REJECT;
|
|
|
|
/*
|
|
* A peer leaves the island immediately if
|
|
* unreachable, synchronized to us or suffers
|
|
* excessive root distance. Careful with the
|
|
* root distance, since the poll interval can
|
|
* increase to a day and a half.
|
|
*/
|
|
if (!peer->reach || (peer->stratum > 1 &&
|
|
peer->refid ==
|
|
peer->dstadr->sin.sin_addr.s_addr) ||
|
|
peer->stratum >= STRATUM_UNSPEC ||
|
|
(root_distance(peer) >= MAXDISTANCE + 2 *
|
|
clock_phi * ULOGTOD(sys_poll)))
|
|
continue;
|
|
|
|
/*
|
|
* Don't allow the local clock or modem drivers
|
|
* in the kitchen at this point, unless the
|
|
* prefer peer. Do that later, but only if
|
|
* nobody else is around. These guys are all
|
|
* configured, so we never throw them away.
|
|
*/
|
|
if (peer->refclktype == REFCLK_LOCALCLOCK
|
|
#if defined(VMS) && defined(VMS_LOCALUNIT)
|
|
/* wjm: local unit VMS_LOCALUNIT taken seriously */
|
|
&& REFCLOCKUNIT(&peer->srcadr) != VMS_LOCALUNIT
|
|
#endif /* VMS && VMS_LOCALUNIT */
|
|
) {
|
|
typelocal = peer;
|
|
if (!(peer->flags & FLAG_PREFER))
|
|
continue; /* no local clock */
|
|
}
|
|
if (peer->sstclktype == CTL_SST_TS_TELEPHONE) {
|
|
typeacts = peer;
|
|
if (!(peer->flags & FLAG_PREFER))
|
|
continue; /* no acts */
|
|
}
|
|
|
|
/*
|
|
* If we get this far, the peer can stay on the
|
|
* island, but does not yet have the immunity
|
|
* idol.
|
|
*/
|
|
nreach++;
|
|
peer->status = CTL_PST_SEL_SANE;
|
|
peer_list[nlist++] = peer;
|
|
|
|
/*
|
|
* Insert each interval endpoint on the sorted
|
|
* list.
|
|
*/
|
|
e = peer->offset; /* Upper end */
|
|
f = root_distance(peer);
|
|
e = e + f;
|
|
for (i = nl3 - 1; i >= 0; i--) {
|
|
if (e >= endpoint[indx[i]].val)
|
|
break;
|
|
indx[i + 3] = indx[i];
|
|
}
|
|
indx[i + 3] = nl3;
|
|
endpoint[nl3].type = 1;
|
|
endpoint[nl3++].val = e;
|
|
|
|
e = e - f; /* Center point */
|
|
for ( ; i >= 0; i--) {
|
|
if (e >= endpoint[indx[i]].val)
|
|
break;
|
|
indx[i + 2] = indx[i];
|
|
}
|
|
indx[i + 2] = nl3;
|
|
endpoint[nl3].type = 0;
|
|
endpoint[nl3++].val = e;
|
|
|
|
e = e - f; /* Lower end */
|
|
for ( ; i >= 0; i--) {
|
|
if (e >= endpoint[indx[i]].val)
|
|
break;
|
|
indx[i + 1] = indx[i];
|
|
}
|
|
indx[i + 1] = nl3;
|
|
endpoint[nl3].type = -1;
|
|
endpoint[nl3++].val = e;
|
|
}
|
|
}
|
|
#ifdef DEBUG
|
|
if (debug > 2)
|
|
for (i = 0; i < nl3; i++)
|
|
printf("select: endpoint %2d %.6f\n",
|
|
endpoint[indx[i]].type,
|
|
endpoint[indx[i]].val);
|
|
#endif
|
|
i = 0;
|
|
j = nl3 - 1;
|
|
allow = nlist; /* falsetickers assumed */
|
|
found = 0;
|
|
while (allow > 0) {
|
|
allow--;
|
|
for (n = 0; i <= j; i++) {
|
|
n += endpoint[indx[i]].type;
|
|
if (n < 0)
|
|
break;
|
|
if (endpoint[indx[i]].type == 0)
|
|
found++;
|
|
}
|
|
for (n = 0; i <= j; j--) {
|
|
n += endpoint[indx[j]].type;
|
|
if (n > 0)
|
|
break;
|
|
if (endpoint[indx[j]].type == 0)
|
|
found++;
|
|
}
|
|
if (found > allow)
|
|
break;
|
|
low = endpoint[indx[i++]].val;
|
|
high = endpoint[indx[j--]].val;
|
|
}
|
|
|
|
/*
|
|
* If no survivors remain at this point, check if the local
|
|
* clock or modem drivers have been found. If so, nominate one
|
|
* of them as the only survivor. Otherwise, give up and declare
|
|
* us unsynchronized.
|
|
*/
|
|
if ((allow << 1) >= nlist) {
|
|
if (typeacts != 0) {
|
|
typeacts->status = CTL_PST_SEL_SANE;
|
|
peer_list[0] = typeacts;
|
|
nlist = 1;
|
|
} else if (typelocal != 0) {
|
|
typelocal->status = CTL_PST_SEL_SANE;
|
|
peer_list[0] = typelocal;
|
|
nlist = 1;
|
|
} else {
|
|
if (osys_peer != NULL) {
|
|
sys_poll = NTP_MINPOLL;
|
|
NLOG(NLOG_SYNCSTATUS)
|
|
msyslog(LOG_INFO,
|
|
"synchronisation lost");
|
|
report_event(EVNT_PEERSTCHG,
|
|
(struct peer *)0);
|
|
}
|
|
sys_survivors = 0;
|
|
#ifdef AUTOKEY
|
|
resetmanycast();
|
|
#endif /* AUTOKEY */
|
|
return;
|
|
}
|
|
}
|
|
#ifdef DEBUG
|
|
if (debug > 2)
|
|
printf("select: low %.6f high %.6f\n", low, high);
|
|
#endif
|
|
|
|
/*
|
|
* Clustering algorithm. Construct candidate list in order first
|
|
* by stratum then by root distance. If we have more than
|
|
* MAXCLOCK peers, keep only the best MAXCLOCK of them. Scan the
|
|
* list to find falsetickers, who leave the island immediately.
|
|
* If a falseticker is not configured, his association raft is
|
|
* drowned as well. We must leave at least one peer to collect
|
|
* the million bucks.
|
|
*/
|
|
j = 0;
|
|
for (i = 0; i < nlist; i++) {
|
|
peer = peer_list[i];
|
|
if (nlist > 1 && (low >= peer->offset || peer->offset >=
|
|
high)) {
|
|
if (!(peer->flags & FLAG_CONFIG))
|
|
unpeer(peer);
|
|
continue;
|
|
}
|
|
peer->status = CTL_PST_SEL_DISTSYSPEER;
|
|
d = root_distance(peer) + peer->stratum * MAXDISPERSE;
|
|
if (j >= NTP_MAXCLOCK) {
|
|
if (d >= synch[j - 1])
|
|
continue;
|
|
else
|
|
j--;
|
|
}
|
|
for (k = j; k > 0; k--) {
|
|
if (d >= synch[k - 1])
|
|
break;
|
|
peer_list[k] = peer_list[k - 1];
|
|
error[k] = error[k - 1];
|
|
synch[k] = synch[k - 1];
|
|
}
|
|
peer_list[k] = peer;
|
|
error[k] = peer->jitter;
|
|
synch[k] = d;
|
|
j++;
|
|
}
|
|
nlist = j;
|
|
for (i = 0; i < nlist; i++) {
|
|
peer_list[i]->status = CTL_PST_SEL_SELCAND;
|
|
|
|
#ifdef DEBUG
|
|
if (debug > 2)
|
|
printf("select: %s distance %.6f\n",
|
|
ntoa(&peer_list[i]->srcadr), synch[i]);
|
|
#endif
|
|
}
|
|
|
|
/*
|
|
* Now, vote outlyers off the island by select jitter weighted
|
|
* by root dispersion. Continue voting as long as there are more
|
|
* than NTP_MINCLOCK survivors and the minimum select jitter
|
|
* squared is greater than the maximum peer jitter squared. Stop
|
|
* if we are about to discard a prefer peer, who of course has
|
|
* the immunity idol.
|
|
*/
|
|
while (1) {
|
|
d = 1e9;
|
|
e = -1e9;
|
|
k = 0;
|
|
for (i = 0; i < nlist; i++) {
|
|
|
|
if (error[i] < d)
|
|
d = error[i];
|
|
f = 0;
|
|
if (nlist > 1) {
|
|
for (j = 0; j < nlist; j++)
|
|
f += DIFF(peer_list[j]->offset,
|
|
peer_list[i]->offset);
|
|
f /= nlist - 1;
|
|
}
|
|
f = max(f, SQUARE(LOGTOD(sys_precision)));
|
|
if (f * synch[i] > e) {
|
|
sys_selerr = f;
|
|
e = f * synch[i];
|
|
k = i;
|
|
}
|
|
}
|
|
|
|
#ifdef DEBUG
|
|
if (debug > 2)
|
|
printf(
|
|
"select: survivors %d select %.6f peer %.6f\n",
|
|
k, SQRT(sys_selerr), SQRT(d));
|
|
#endif
|
|
if (nlist <= NTP_MINCLOCK || sys_selerr <= d ||
|
|
peer_list[k]->flags & FLAG_PREFER)
|
|
break;
|
|
if (!(peer_list[k]->flags & FLAG_CONFIG))
|
|
unpeer(peer_list[k]);
|
|
for (j = k + 1; j < nlist; j++) {
|
|
peer_list[j - 1] = peer_list[j];
|
|
error[j - 1] = error[j];
|
|
}
|
|
nlist--;
|
|
}
|
|
|
|
#ifdef AUTOKEY
|
|
/*
|
|
* In manycast client mode we may have spooked a sizeable number
|
|
* of servers that we don't need. If there are at least
|
|
* NTP_MINCLOCK of them, the manycast message will be turned
|
|
* off. By the time we get here we nay be ready to prune some of
|
|
* them back, but we want to make sure all the candicates have
|
|
* had a chance. If they didn't pass the sanity and intersection
|
|
* tests, they have already been voted off the island.
|
|
*/
|
|
if (sys_survivors >= NTP_MINCLOCK && nlist < NTP_MINCLOCK)
|
|
resetmanycast();
|
|
#endif /* AUTOKEY */
|
|
sys_survivors = nlist;
|
|
|
|
#ifdef DEBUG
|
|
if (debug > 2) {
|
|
for (i = 0; i < nlist; i++)
|
|
printf(
|
|
"select: %s offset %.6f, distance %.6f poll %d\n",
|
|
ntoa(&peer_list[i]->srcadr),
|
|
peer_list[i]->offset, synch[i],
|
|
peer_list[i]->pollsw);
|
|
}
|
|
#endif
|
|
|
|
/*
|
|
* What remains is a list of not greater than NTP_MINCLOCK
|
|
* peers. We want only a peer at the lowest stratum to become
|
|
* the system peer, although all survivors are eligible for the
|
|
* combining algorithm. First record their order, diddle the
|
|
* flags and clamp the poll intervals. Then, consider the peers
|
|
* at the lowest stratum. Of these, OR the leap bits on the
|
|
* assumption that, if some of them honk nonzero bits, they must
|
|
* know what they are doing. Also, check for prefer and pps
|
|
* peers. If a prefer peer is found within clock_max, update the
|
|
* pps switch. Of the other peers not at the lowest stratum,
|
|
* check if the system peer is among them and, if found, zap
|
|
* him. We note that the head of the list is at the lowest
|
|
* stratum and that unsynchronized peers cannot survive this
|
|
* far.
|
|
*
|
|
* Note that we go no further, unless the number of survivors is
|
|
* a majority of the suckers that have been found reachable and
|
|
* no prior source is available. This avoids the transient when
|
|
* one of a flock of sources is out to lunch and just happens
|
|
* to be the first survivor.
|
|
*/
|
|
if (osys_peer == NULL && 2 * nlist < min(nreach, NTP_MINCLOCK))
|
|
return;
|
|
leap_consensus = 0;
|
|
for (i = nlist - 1; i >= 0; i--) {
|
|
peer = peer_list[i];
|
|
peer->status = CTL_PST_SEL_SYNCCAND;
|
|
peer->flags |= FLAG_SYSPEER;
|
|
poll_update(peer, peer->hpoll);
|
|
if (peer->stratum == peer_list[0]->stratum) {
|
|
leap_consensus |= peer->leap;
|
|
if (peer->refclktype == REFCLK_ATOM_PPS &&
|
|
peer->stratum < STRATUM_UNSPEC)
|
|
typepps = peer;
|
|
if (peer == osys_peer)
|
|
typesystem = peer;
|
|
if (peer->flags & FLAG_PREFER)
|
|
sys_prefer = peer;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Mitigation rules of the game. There are several types of
|
|
* peers that make a difference here: (1) prefer local peers
|
|
* (type REFCLK_LOCALCLOCK with FLAG_PREFER) or prefer modem
|
|
* peers (type REFCLK_NIST_ATOM etc with FLAG_PREFER), (2) pps
|
|
* peers (type REFCLK_ATOM_PPS), (3) remaining prefer peers
|
|
* (flag FLAG_PREFER), (4) the existing system peer, if any, (5)
|
|
* the head of the survivor list. Note that only one peer can be
|
|
* declared prefer. The order of preference is in the order
|
|
* stated. Note that all of these must be at the lowest stratum,
|
|
* i.e., the stratum of the head of the survivor list.
|
|
*/
|
|
if (sys_prefer)
|
|
sw = sys_prefer->refclktype == REFCLK_LOCALCLOCK ||
|
|
sys_prefer->sstclktype == CTL_SST_TS_TELEPHONE ||
|
|
!typepps;
|
|
else
|
|
sw = 0;
|
|
if (sw) {
|
|
sys_peer = sys_prefer;
|
|
sys_peer->status = CTL_PST_SEL_SYSPEER;
|
|
sys_offset = sys_peer->offset;
|
|
sys_syserr = sys_peer->jitter;
|
|
#ifdef DEBUG
|
|
if (debug > 1)
|
|
printf("select: prefer offset %.6f\n",
|
|
sys_offset);
|
|
#endif
|
|
} else if (typepps) {
|
|
sys_peer = typepps;
|
|
sys_peer->status = CTL_PST_SEL_PPS;
|
|
sys_offset = sys_peer->offset;
|
|
sys_syserr = sys_peer->jitter;
|
|
if (!pps_control)
|
|
NLOG(NLOG_SYSEVENT)
|
|
msyslog(LOG_INFO,
|
|
"pps sync enabled");
|
|
pps_control = current_time;
|
|
#ifdef DEBUG
|
|
if (debug > 1)
|
|
printf("select: pps offset %.6f\n",
|
|
sys_offset);
|
|
#endif
|
|
} else {
|
|
if (typesystem)
|
|
sys_peer = osys_peer;
|
|
else
|
|
sys_peer = peer_list[0];
|
|
sys_peer->status = CTL_PST_SEL_SYSPEER;
|
|
sys_offset = clock_combine(peer_list, nlist);
|
|
sys_syserr = sys_peer->jitter + sys_selerr;
|
|
#ifdef DEBUG
|
|
if (debug > 1)
|
|
printf("select: combine offset %.6f\n",
|
|
sys_offset);
|
|
#endif
|
|
}
|
|
if (osys_peer != sys_peer)
|
|
report_event(EVNT_PEERSTCHG, (struct peer *)0);
|
|
clock_update();
|
|
}
|
|
|
|
/*
|
|
* clock_combine - combine offsets from selected peers
|
|
*/
|
|
static double
|
|
clock_combine(
|
|
struct peer **peers,
|
|
int npeers
|
|
)
|
|
{
|
|
int i;
|
|
double x, y, z;
|
|
y = z = 0;
|
|
for (i = 0; i < npeers; i++) {
|
|
x = root_distance(peers[i]);
|
|
y += 1. / x;
|
|
z += peers[i]->offset / x;
|
|
}
|
|
return (z / y);
|
|
}
|
|
|
|
/*
|
|
* root_distance - compute synchronization distance from peer to root
|
|
*/
|
|
static double
|
|
root_distance(
|
|
struct peer *peer
|
|
)
|
|
{
|
|
/*
|
|
* Careful squeak here. The value returned must be greater than
|
|
* zero blamed on the peer jitter, which must be at least the
|
|
* square of sys_precision.
|
|
*/
|
|
return ((peer->rootdelay + peer->delay) / 2 +
|
|
peer->rootdispersion + peer->disp + clock_phi *
|
|
(current_time - peer->update) + SQRT(peer->jitter));
|
|
}
|
|
|
|
/*
|
|
* peer_xmit - send packet for persistent association.
|
|
*/
|
|
static void
|
|
peer_xmit(
|
|
struct peer *peer /* peer structure pointer */
|
|
)
|
|
{
|
|
struct pkt xpkt; /* transmit packet */
|
|
int sendlen, authlen;
|
|
keyid_t xkeyid; /* transmit key ID */
|
|
l_fp xmt_tx;
|
|
|
|
/*
|
|
* Initialize transmit packet header fields.
|
|
*/
|
|
xpkt.li_vn_mode = PKT_LI_VN_MODE(sys_leap, peer->version,
|
|
peer->hmode);
|
|
xpkt.stratum = STRATUM_TO_PKT(sys_stratum);
|
|
xpkt.ppoll = peer->hpoll;
|
|
xpkt.precision = sys_precision;
|
|
xpkt.rootdelay = HTONS_FP(DTOFP(sys_rootdelay));
|
|
xpkt.rootdispersion = HTONS_FP(DTOUFP(sys_rootdispersion));
|
|
xpkt.refid = sys_refid;
|
|
HTONL_FP(&sys_reftime, &xpkt.reftime);
|
|
HTONL_FP(&peer->org, &xpkt.org);
|
|
HTONL_FP(&peer->rec, &xpkt.rec);
|
|
|
|
/*
|
|
* If the received packet contains a MAC, the transmitted packet
|
|
* is authenticated and contains a MAC. If not, the transmitted
|
|
* packet is not authenticated.
|
|
*
|
|
* In the current I/O semantics the default interface is set
|
|
* until after receiving a packet and setting the right
|
|
* interface. So, the first packet goes out unauthenticated.
|
|
* That's why the really icky test next is here.
|
|
*/
|
|
sendlen = LEN_PKT_NOMAC;
|
|
if (!(peer->flags & FLAG_AUTHENABLE)) {
|
|
get_systime(&peer->xmt);
|
|
HTONL_FP(&peer->xmt, &xpkt.xmt);
|
|
sendpkt(&peer->srcadr, peer->dstadr, peer->ttl, &xpkt,
|
|
sendlen);
|
|
peer->sent++;
|
|
#ifdef DEBUG
|
|
if (debug)
|
|
printf("transmit: at %ld %s->%s mode %d\n",
|
|
current_time, ntoa(&peer->dstadr->sin),
|
|
ntoa(&peer->srcadr), peer->hmode);
|
|
#endif
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* The received packet contains a MAC, so the transmitted packet
|
|
* must be authenticated. If autokey is enabled, fuss with the
|
|
* various modes; otherwise, private key cryptography is used.
|
|
*/
|
|
#ifdef AUTOKEY
|
|
if ((peer->flags & FLAG_SKEY)) {
|
|
u_int cmmd;
|
|
|
|
/*
|
|
* The Public Key Dance (PKD): Cryptographic credentials
|
|
* are contained in extension fields, each including a
|
|
* 4-octet length/code word followed by a 4-octet
|
|
* association ID and optional additional data. Optional
|
|
* data includes a 4-octet data length field followed by
|
|
* the data itself. Request messages are sent from a
|
|
* configured association; response messages can be sent
|
|
* from a configured association or can take the fast
|
|
* path without ever matching an association. Response
|
|
* messages have the same code as the request, but have
|
|
* a response bit and possibly an error bit set. In this
|
|
* implementation, a message may contain no more than
|
|
* one command and no more than one response.
|
|
*
|
|
* Cryptographic session keys include both a public and
|
|
* a private componet. Request and response messages
|
|
* using extension fields are always sent with the
|
|
* private component set to zero. Packets without
|
|
* extension fields indlude the private component when
|
|
* the session key is generated.
|
|
*/
|
|
while (1) {
|
|
|
|
/*
|
|
* Allocate and initialize a keylist if not
|
|
* already done. Then, use the list in inverse
|
|
* order, discarding keys once used. Keep the
|
|
* latest key around until the next one, so
|
|
* clients can use client/server packets to
|
|
* compute propagation delay.
|
|
*
|
|
* Note that once a key is used from the list,
|
|
* it is retained in the key cache until the
|
|
* next key is used. This is to allow a client
|
|
* to retrieve the encrypted session key
|
|
* identifier to verify authenticity.
|
|
*
|
|
* If for some reason a key is no longer in the
|
|
* key cache, a birthday has happened and the
|
|
* pseudo-random sequence is probably broken. In
|
|
* that case, purge the keylist and regenerate
|
|
* it.
|
|
*/
|
|
if (peer->keynumber == 0)
|
|
make_keylist(peer, peer->dstadr);
|
|
else
|
|
peer->keynumber--;
|
|
xkeyid = peer->keylist[peer->keynumber];
|
|
if (authistrusted(xkeyid))
|
|
break;
|
|
else
|
|
key_expire(peer);
|
|
}
|
|
peer->keyid = xkeyid;
|
|
switch (peer->hmode) {
|
|
|
|
/*
|
|
* In broadcast mode the autokey values are required.
|
|
* Send them when a new keylist is generated; otherwise,
|
|
* send the association ID so the client can request
|
|
* them at other times.
|
|
*/
|
|
case MODE_BROADCAST:
|
|
if (peer->flags & FLAG_ASSOC)
|
|
cmmd = CRYPTO_AUTO | CRYPTO_RESP;
|
|
else
|
|
cmmd = CRYPTO_ASSOC | CRYPTO_RESP;
|
|
sendlen += crypto_xmit((u_int32 *)&xpkt,
|
|
sendlen, cmmd, 0, peer->associd);
|
|
break;
|
|
|
|
/*
|
|
* In symmetric modes the public key, leapsecond table,
|
|
* agreement parameters and autokey values are required.
|
|
*
|
|
* 1. If a response is pending, always send it first.
|
|
*
|
|
* 2. Don't send anything except a public-key request
|
|
* until the public key has been stored.
|
|
*
|
|
* 3. Once the public key has been stored, don't send
|
|
* anything except an agreement parameter request
|
|
* until the agreement parameters have been stored.
|
|
*
|
|
* 4. Once the argeement parameters have been stored,
|
|
* don't send anything except a public value request
|
|
* until the agreed key has been stored.
|
|
*
|
|
* 5. When the agreed key has been stored and the key
|
|
* list is regenerated, send the autokey values
|
|
* gratis unless they have already been sent.
|
|
*/
|
|
case MODE_ACTIVE:
|
|
case MODE_PASSIVE:
|
|
#ifdef PUBKEY
|
|
if (peer->cmmd != 0)
|
|
sendlen += crypto_xmit((u_int32 *)&xpkt,
|
|
sendlen, (peer->cmmd >> 16) |
|
|
CRYPTO_RESP, peer->hcookie,
|
|
peer->associd);
|
|
if (!peer->crypto)
|
|
sendlen += crypto_xmit((u_int32 *)&xpkt,
|
|
sendlen, CRYPTO_ASSOC,
|
|
peer->hcookie, peer->assoc);
|
|
else if (!crypto_flags &&
|
|
peer->pcookie.tstamp == 0 && sys_leap !=
|
|
LEAP_NOTINSYNC)
|
|
sendlen += crypto_xmit((u_int32 *)&xpkt,
|
|
sendlen, CRYPTO_PRIV, peer->hcookie,
|
|
peer->assoc);
|
|
else if (crypto_flags && peer->pubkey.ptr ==
|
|
NULL)
|
|
sendlen += crypto_xmit((u_int32 *)&xpkt,
|
|
sendlen, CRYPTO_NAME, peer->hcookie,
|
|
peer->assoc);
|
|
else if (peer->crypto & CRYPTO_FLAG_CERT)
|
|
sendlen += crypto_xmit((u_int32 *)&xpkt,
|
|
sendlen, CRYPTO_CERT, peer->hcookie,
|
|
peer->assoc);
|
|
else if (crypto_flags && peer->crypto &
|
|
CRYPTO_FLAG_DH && sys_leap !=
|
|
LEAP_NOTINSYNC)
|
|
sendlen += crypto_xmit((u_int32 *)&xpkt,
|
|
sendlen, CRYPTO_DHPAR,
|
|
peer->hcookie, peer->assoc);
|
|
else if (crypto_flags && peer->pcookie.tstamp ==
|
|
0 && sys_leap != LEAP_NOTINSYNC)
|
|
sendlen += crypto_xmit((u_int32 *)&xpkt,
|
|
sendlen, CRYPTO_DH, peer->hcookie,
|
|
peer->assoc);
|
|
#else
|
|
if (peer->cmmd != 0)
|
|
sendlen += crypto_xmit((u_int32 *)&xpkt,
|
|
sendlen, (peer->cmmd >> 16) |
|
|
CRYPTO_RESP, peer->hcookie,
|
|
peer->associd);
|
|
if (peer->pcookie.tstamp == 0 && sys_leap !=
|
|
LEAP_NOTINSYNC)
|
|
sendlen += crypto_xmit((u_int32 *)&xpkt,
|
|
sendlen, CRYPTO_PRIV, peer->hcookie,
|
|
peer->assoc);
|
|
#endif /* PUBKEY */
|
|
else if (!(peer->flags & FLAG_AUTOKEY))
|
|
sendlen += crypto_xmit((u_int32 *)&xpkt,
|
|
sendlen, CRYPTO_AUTO, peer->hcookie,
|
|
peer->assoc);
|
|
else if ((peer->flags & FLAG_ASSOC) &&
|
|
(peer->cmmd >> 16) != CRYPTO_AUTO)
|
|
sendlen += crypto_xmit((u_int32 *)&xpkt,
|
|
sendlen, CRYPTO_AUTO | CRYPTO_RESP,
|
|
peer->hcookie, peer->associd);
|
|
#ifdef PUBKEY
|
|
else if (peer->crypto & CRYPTO_FLAG_TAI)
|
|
sendlen += crypto_xmit((u_int32 *)&xpkt,
|
|
sendlen, CRYPTO_TAI, peer->hcookie,
|
|
peer->assoc);
|
|
#endif /* PUBKEY */
|
|
peer->cmmd = 0;
|
|
break;
|
|
|
|
/*
|
|
* In client mode, the public key, host cookie and
|
|
* autokey values are required. In broadcast client
|
|
* mode, these values must be acquired during the
|
|
* client/server exchange to avoid having to wait until
|
|
* the next key list regeneration. Otherwise, the poor
|
|
* dude may die a lingering death until becoming
|
|
* unreachable and attempting rebirth. Note that we ask
|
|
* for the cookie at each key list regeneration anyway.
|
|
*/
|
|
case MODE_CLIENT:
|
|
if (peer->cmmd != 0)
|
|
sendlen += crypto_xmit((u_int32 *)&xpkt,
|
|
sendlen, (peer->cmmd >> 16) |
|
|
CRYPTO_RESP, peer->hcookie,
|
|
peer->associd);
|
|
if (!peer->crypto)
|
|
sendlen += crypto_xmit((u_int32 *)&xpkt,
|
|
sendlen, CRYPTO_ASSOC,
|
|
peer->hcookie, peer->assoc);
|
|
#ifdef PUBKEY
|
|
else if (crypto_flags && peer->pubkey.ptr ==
|
|
NULL)
|
|
sendlen += crypto_xmit((u_int32 *)&xpkt,
|
|
sendlen, CRYPTO_NAME, peer->hcookie,
|
|
peer->assoc);
|
|
else if (peer->crypto & CRYPTO_FLAG_CERT)
|
|
sendlen += crypto_xmit((u_int32 *)&xpkt,
|
|
sendlen, CRYPTO_CERT, peer->hcookie,
|
|
peer->assoc);
|
|
#endif /* PUBKEY */
|
|
else if (peer->pcookie.tstamp == 0)
|
|
sendlen += crypto_xmit((u_int32 *)&xpkt,
|
|
sendlen, CRYPTO_PRIV, peer->hcookie,
|
|
peer->assoc);
|
|
else if (!(peer->flags & FLAG_AUTOKEY) &&
|
|
(peer->cast_flags & MDF_BCLNT))
|
|
sendlen += crypto_xmit((u_int32 *)&xpkt,
|
|
sendlen, CRYPTO_AUTO, peer->hcookie,
|
|
peer->assoc);
|
|
#ifdef PUBKEY
|
|
else if (peer->crypto & CRYPTO_FLAG_TAI)
|
|
sendlen += crypto_xmit((u_int32 *)&xpkt,
|
|
sendlen, CRYPTO_TAI, peer->hcookie,
|
|
peer->assoc);
|
|
#endif /* PUBKEY */
|
|
peer->cmmd = 0;
|
|
break;
|
|
}
|
|
|
|
/*
|
|
* If extension fields are present, we must use a
|
|
* private value of zero and force min poll interval.
|
|
* Most intricate.
|
|
*/
|
|
if (sendlen > LEN_PKT_NOMAC)
|
|
session_key(&peer->dstadr->sin, &peer->srcadr,
|
|
xkeyid, 0, 2);
|
|
}
|
|
#endif /* AUTOKEY */
|
|
xkeyid = peer->keyid;
|
|
get_systime(&peer->xmt);
|
|
L_ADD(&peer->xmt, &sys_authdelay);
|
|
HTONL_FP(&peer->xmt, &xpkt.xmt);
|
|
authlen = authencrypt(xkeyid, (u_int32 *)&xpkt, sendlen);
|
|
if (authlen == 0) {
|
|
msyslog(LOG_NOTICE,
|
|
"transmit: no encryption key found");
|
|
peer->flash |= TEST4 | TEST5;
|
|
return;
|
|
}
|
|
sendlen += authlen;
|
|
#ifdef AUTOKEY
|
|
if (xkeyid > NTP_MAXKEY)
|
|
authtrust(xkeyid, 0);
|
|
#endif /* AUTOKEY */
|
|
get_systime(&xmt_tx);
|
|
if (sendlen > sizeof(xpkt)) {
|
|
msyslog(LOG_ERR, "buffer overflow %u", sendlen);
|
|
exit(-1);
|
|
}
|
|
sendpkt(&peer->srcadr, peer->dstadr, peer->ttl, &xpkt, sendlen);
|
|
|
|
/*
|
|
* Calculate the encryption delay. Keep the minimum over
|
|
* the latest two samples.
|
|
*/
|
|
L_SUB(&xmt_tx, &peer->xmt);
|
|
L_ADD(&xmt_tx, &sys_authdelay);
|
|
sys_authdly[1] = sys_authdly[0];
|
|
sys_authdly[0] = xmt_tx.l_uf;
|
|
if (sys_authdly[0] < sys_authdly[1])
|
|
sys_authdelay.l_uf = sys_authdly[0];
|
|
else
|
|
sys_authdelay.l_uf = sys_authdly[1];
|
|
peer->sent++;
|
|
#ifdef AUTOKEY
|
|
#ifdef DEBUG
|
|
if (debug)
|
|
printf(
|
|
"transmit: at %ld %s->%s mode %d keyid %08x len %d mac %d index %d\n",
|
|
current_time, ntoa(&peer->dstadr->sin),
|
|
ntoa(&peer->srcadr), peer->hmode, xkeyid, sendlen,
|
|
authlen, peer->keynumber);
|
|
#endif
|
|
#else
|
|
#ifdef DEBUG
|
|
if (debug)
|
|
printf(
|
|
"transmit: at %ld %s->%s mode %d keyid %08x len %d mac %d\n",
|
|
current_time, ntoa(&peer->dstadr->sin),
|
|
ntoa(&peer->srcadr), peer->hmode, xkeyid, sendlen,
|
|
authlen);
|
|
#endif
|
|
#endif /* AUTOKEY */
|
|
}
|
|
|
|
|
|
/*
|
|
* fast_xmit - Send packet for nonpersistent association. Note that
|
|
* neither the source or destination can be a broadcast address.
|
|
*/
|
|
static void
|
|
fast_xmit(
|
|
struct recvbuf *rbufp, /* receive packet pointer */
|
|
int xmode, /* transmit mode */
|
|
keyid_t xkeyid, /* transmit key ID */
|
|
int mask /* restrict mask */
|
|
)
|
|
{
|
|
struct pkt xpkt; /* transmit packet structure */
|
|
struct pkt *rpkt; /* receive packet structure */
|
|
l_fp xmt_ts; /* transmit timestamp */
|
|
l_fp xmt_tx; /* transmit timestamp after authent */
|
|
int sendlen, authlen;
|
|
|
|
/*
|
|
* Initialize transmit packet header fields from the receive
|
|
* buffer provided. We leave some fields intact as received. If
|
|
* the gazinta was from a multicast address, the gazouta must go
|
|
* out another way.
|
|
*/
|
|
rpkt = &rbufp->recv_pkt;
|
|
if (rbufp->dstadr->flags & INT_MULTICAST)
|
|
rbufp->dstadr = findinterface(&rbufp->recv_srcadr);
|
|
|
|
/*
|
|
* If the caller is restricted, return a kiss-of-death packet;
|
|
* otherwise, smooch politely.
|
|
*/
|
|
if (mask & (RES_DONTSERVE | RES_LIMITED)) {
|
|
if (!(mask & RES_DEMOBILIZE)) {
|
|
return;
|
|
} else {
|
|
xpkt.li_vn_mode =
|
|
PKT_LI_VN_MODE(LEAP_NOTINSYNC,
|
|
PKT_VERSION(rpkt->li_vn_mode), xmode);
|
|
xpkt.stratum = STRATUM_UNSPEC;
|
|
memcpy(&xpkt.refid, "DENY", 4);
|
|
}
|
|
} else {
|
|
xpkt.li_vn_mode = PKT_LI_VN_MODE(sys_leap,
|
|
PKT_VERSION(rpkt->li_vn_mode), xmode);
|
|
xpkt.stratum = STRATUM_TO_PKT(sys_stratum);
|
|
xpkt.refid = sys_refid;
|
|
}
|
|
xpkt.ppoll = rpkt->ppoll;
|
|
xpkt.precision = sys_precision;
|
|
xpkt.rootdelay = HTONS_FP(DTOFP(sys_rootdelay));
|
|
xpkt.rootdispersion =
|
|
HTONS_FP(DTOUFP(sys_rootdispersion));
|
|
HTONL_FP(&sys_reftime, &xpkt.reftime);
|
|
xpkt.org = rpkt->xmt;
|
|
HTONL_FP(&rbufp->recv_time, &xpkt.rec);
|
|
|
|
/*
|
|
* If the received packet contains a MAC, the transmitted packet
|
|
* is authenticated and contains a MAC. If not, the transmitted
|
|
* packet is not authenticated.
|
|
*/
|
|
sendlen = LEN_PKT_NOMAC;
|
|
if (rbufp->recv_length == sendlen) {
|
|
get_systime(&xmt_ts);
|
|
HTONL_FP(&xmt_ts, &xpkt.xmt);
|
|
sendpkt(&rbufp->recv_srcadr, rbufp->dstadr, 0, &xpkt,
|
|
sendlen);
|
|
#ifdef DEBUG
|
|
if (debug)
|
|
printf("transmit: at %ld %s->%s mode %d\n",
|
|
current_time, ntoa(&rbufp->dstadr->sin),
|
|
ntoa(&rbufp->recv_srcadr), xmode);
|
|
#endif
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* The received packet contains a MAC, so the transmitted packet
|
|
* must be authenticated. For private-key cryptography, use the
|
|
* predefined private keys to generate the cryptosum. For
|
|
* autokey cryptography, use the server private value to
|
|
* generate the cookie, which is unique for every source-
|
|
* destination-key ID combination.
|
|
*/
|
|
#ifdef AUTOKEY
|
|
if (xkeyid > NTP_MAXKEY) {
|
|
keyid_t cookie;
|
|
u_int code, associd;
|
|
|
|
/*
|
|
* The only way to get here is a reply to a legitimate
|
|
* client request message, so the mode must be
|
|
* MODE_SERVER. If an extension field is present, there
|
|
* can be only one and that must be a command. Do what
|
|
* needs, but with private value of zero so the poor
|
|
* jerk can decode it. If no extension field is present,
|
|
* use the cookie to generate the session key.
|
|
*/
|
|
code = (htonl(rpkt->exten[0]) >> 16) | CRYPTO_RESP;
|
|
cookie = session_key(&rbufp->recv_srcadr,
|
|
&rbufp->dstadr->sin, 0, sys_private, 0);
|
|
associd = htonl(rpkt->exten[1]);
|
|
if (rbufp->recv_length >= sendlen + MAX_MAC_LEN + 2 *
|
|
sizeof(u_int32)) {
|
|
session_key(&rbufp->dstadr->sin,
|
|
&rbufp->recv_srcadr, xkeyid, 0, 2);
|
|
sendlen += crypto_xmit((u_int32 *)&xpkt,
|
|
sendlen, code, cookie, associd);
|
|
} else {
|
|
session_key(&rbufp->dstadr->sin,
|
|
&rbufp->recv_srcadr, xkeyid, cookie, 2);
|
|
}
|
|
}
|
|
#endif /* AUTOKEY */
|
|
get_systime(&xmt_ts);
|
|
L_ADD(&xmt_ts, &sys_authdelay);
|
|
HTONL_FP(&xmt_ts, &xpkt.xmt);
|
|
authlen = authencrypt(xkeyid, (u_int32 *)&xpkt, sendlen);
|
|
sendlen += authlen;
|
|
#ifdef AUTOKEY
|
|
if (xkeyid > NTP_MAXKEY)
|
|
authtrust(xkeyid, 0);
|
|
#endif /* AUTOKEY */
|
|
get_systime(&xmt_tx);
|
|
if (sendlen > sizeof(xpkt)) {
|
|
msyslog(LOG_ERR, "buffer overflow %u", sendlen);
|
|
exit(-1);
|
|
}
|
|
sendpkt(&rbufp->recv_srcadr, rbufp->dstadr, 0, &xpkt, sendlen);
|
|
|
|
/*
|
|
* Calculate the encryption delay. Keep the minimum over the
|
|
* latest two samples.
|
|
*/
|
|
L_SUB(&xmt_tx, &xmt_ts);
|
|
L_ADD(&xmt_tx, &sys_authdelay);
|
|
sys_authdly[1] = sys_authdly[0];
|
|
sys_authdly[0] = xmt_tx.l_uf;
|
|
if (sys_authdly[0] < sys_authdly[1])
|
|
sys_authdelay.l_uf = sys_authdly[0];
|
|
else
|
|
sys_authdelay.l_uf = sys_authdly[1];
|
|
#ifdef DEBUG
|
|
if (debug)
|
|
printf(
|
|
"transmit: at %ld %s->%s mode %d keyid %08x len %d mac %d\n",
|
|
current_time, ntoa(&rbufp->dstadr->sin),
|
|
ntoa(&rbufp->recv_srcadr), xmode, xkeyid, sendlen,
|
|
authlen);
|
|
#endif
|
|
}
|
|
|
|
|
|
#ifdef AUTOKEY
|
|
/*
|
|
* key_expire - purge the key list
|
|
*/
|
|
void
|
|
key_expire(
|
|
struct peer *peer /* peer structure pointer */
|
|
)
|
|
{
|
|
int i;
|
|
|
|
if (peer->keylist != NULL) {
|
|
for (i = 0; i <= peer->keynumber; i++)
|
|
authtrust(peer->keylist[i], 0);
|
|
free(peer->keylist);
|
|
peer->keylist = NULL;
|
|
}
|
|
peer->keynumber = peer->sndauto.seq = 0;
|
|
#ifdef DEBUG
|
|
if (debug)
|
|
printf("key_expire: at %lu\n", current_time);
|
|
#endif
|
|
}
|
|
#endif /* AUTOKEY */
|
|
|
|
/*
|
|
* Find the precision of this particular machine
|
|
*/
|
|
#define DUSECS 1000000 /* us in a s */
|
|
#define HUSECS (1 << 20) /* approx DUSECS for shifting etc */
|
|
#define MINSTEP 5 /* minimum clock increment (us) */
|
|
#define MAXSTEP 20000 /* maximum clock increment (us) */
|
|
#define MINLOOPS 5 /* minimum number of step samples */
|
|
|
|
/*
|
|
* This routine calculates the differences between successive calls to
|
|
* gettimeofday(). If a difference is less than zero, the us field
|
|
* has rolled over to the next second, so we add a second in us. If
|
|
* the difference is greater than zero and less than MINSTEP, the
|
|
* clock has been advanced by a small amount to avoid standing still.
|
|
* If the clock has advanced by a greater amount, then a timer interrupt
|
|
* has occurred and this amount represents the precision of the clock.
|
|
* In order to guard against spurious values, which could occur if we
|
|
* happen to hit a fat interrupt, we do this for MINLOOPS times and
|
|
* keep the minimum value obtained.
|
|
*/
|
|
int
|
|
default_get_precision(void)
|
|
{
|
|
struct timeval tp;
|
|
#if !defined(SYS_WINNT) && !defined(VMS) && !defined(_SEQUENT_)
|
|
struct timezone tzp;
|
|
#elif defined(VMS) || defined(_SEQUENT_)
|
|
struct timezone {
|
|
int tz_minuteswest;
|
|
int tz_dsttime;
|
|
} tzp;
|
|
#endif /* defined(VMS) || defined(_SEQUENT_) */
|
|
long last;
|
|
int i;
|
|
long diff;
|
|
long val;
|
|
long usec;
|
|
#ifdef HAVE_GETCLOCK
|
|
struct timespec ts;
|
|
#endif
|
|
#if defined(__FreeBSD__) && __FreeBSD__ >= 3
|
|
u_long freq;
|
|
size_t j;
|
|
|
|
/* Try to see if we can find the frequency of of the counter
|
|
* which drives our timekeeping
|
|
*/
|
|
j = sizeof freq;
|
|
i = sysctlbyname("kern.timecounter.frequency", &freq, &j , 0,
|
|
0);
|
|
if (i)
|
|
i = sysctlbyname("machdep.tsc_freq", &freq, &j , 0, 0);
|
|
if (i)
|
|
i = sysctlbyname("machdep.i586_freq", &freq, &j , 0, 0);
|
|
if (i)
|
|
i = sysctlbyname("machdep.i8254_freq", &freq, &j , 0,
|
|
0);
|
|
if (!i) {
|
|
for (i = 1; freq ; i--)
|
|
freq >>= 1;
|
|
return (i);
|
|
}
|
|
#endif
|
|
usec = 0;
|
|
val = MAXSTEP;
|
|
#ifdef HAVE_GETCLOCK
|
|
(void) getclock(TIMEOFDAY, &ts);
|
|
tp.tv_sec = ts.tv_sec;
|
|
tp.tv_usec = ts.tv_nsec / 1000;
|
|
#else /* not HAVE_GETCLOCK */
|
|
GETTIMEOFDAY(&tp, &tzp);
|
|
#endif /* not HAVE_GETCLOCK */
|
|
last = tp.tv_usec;
|
|
for (i = 0; i < MINLOOPS && usec < HUSECS;) {
|
|
#ifdef HAVE_GETCLOCK
|
|
(void) getclock(TIMEOFDAY, &ts);
|
|
tp.tv_sec = ts.tv_sec;
|
|
tp.tv_usec = ts.tv_nsec / 1000;
|
|
#else /* not HAVE_GETCLOCK */
|
|
GETTIMEOFDAY(&tp, &tzp);
|
|
#endif /* not HAVE_GETCLOCK */
|
|
diff = tp.tv_usec - last;
|
|
last = tp.tv_usec;
|
|
if (diff < 0)
|
|
diff += DUSECS;
|
|
usec += diff;
|
|
if (diff > MINSTEP) {
|
|
i++;
|
|
if (diff < val)
|
|
val = diff;
|
|
}
|
|
}
|
|
NLOG(NLOG_SYSINFO)
|
|
msyslog(LOG_INFO, "precision = %ld usec", val);
|
|
if (usec >= HUSECS)
|
|
val = MINSTEP; /* val <= MINSTEP; fast machine */
|
|
diff = HUSECS;
|
|
for (i = 0; diff > val; i--)
|
|
diff >>= 1;
|
|
return (i);
|
|
}
|
|
|
|
/*
|
|
* init_proto - initialize the protocol module's data
|
|
*/
|
|
void
|
|
init_proto(void)
|
|
{
|
|
l_fp dummy;
|
|
|
|
/*
|
|
* Fill in the sys_* stuff. Default is don't listen to
|
|
* broadcasting, authenticate.
|
|
*/
|
|
sys_leap = LEAP_NOTINSYNC;
|
|
sys_stratum = STRATUM_UNSPEC;
|
|
sys_precision = (s_char)default_get_precision();
|
|
sys_jitter = LOGTOD(sys_precision);
|
|
sys_rootdelay = 0;
|
|
sys_rootdispersion = 0;
|
|
sys_refid = 0;
|
|
L_CLR(&sys_reftime);
|
|
sys_peer = NULL;
|
|
sys_survivors = 0;
|
|
get_systime(&dummy);
|
|
sys_bclient = 0;
|
|
sys_bdelay = DEFBROADDELAY;
|
|
sys_authenticate = 1;
|
|
L_CLR(&sys_authdelay);
|
|
sys_authdly[0] = sys_authdly[1] = 0;
|
|
sys_stattime = 0;
|
|
sys_badstratum = 0;
|
|
sys_oldversionpkt = 0;
|
|
sys_newversionpkt = 0;
|
|
sys_badlength = 0;
|
|
sys_unknownversion = 0;
|
|
sys_processed = 0;
|
|
sys_badauth = 0;
|
|
sys_manycastserver = 0;
|
|
#ifdef AUTOKEY
|
|
sys_automax = 1 << NTP_AUTOMAX;
|
|
#endif /* AUTOKEY */
|
|
|
|
/*
|
|
* Default these to enable
|
|
*/
|
|
ntp_enable = 1;
|
|
#ifndef KERNEL_FLL_BUG
|
|
kern_enable = 1;
|
|
#endif
|
|
pps_enable = 0;
|
|
stats_control = 1;
|
|
|
|
/*
|
|
* Some system clocks should only be adjusted in 10ms
|
|
* increments.
|
|
*/
|
|
#if defined RELIANTUNIX_CLOCK
|
|
systime_10ms_ticks = 1; /* Reliant UNIX */
|
|
#elif defined SCO5_CLOCK
|
|
if (sys_precision >= (s_char)-10) /* pre-SCO OpenServer 5.0.6 */
|
|
systime_10ms_ticks = 1;
|
|
#endif
|
|
if (systime_10ms_ticks)
|
|
msyslog(LOG_INFO, "using 10ms tick adjustments");
|
|
}
|
|
|
|
|
|
/*
|
|
* proto_config - configure the protocol module
|
|
*/
|
|
void
|
|
proto_config(
|
|
int item,
|
|
u_long value,
|
|
double dvalue
|
|
)
|
|
{
|
|
/*
|
|
* Figure out what he wants to change, then do it
|
|
*/
|
|
switch (item) {
|
|
case PROTO_KERNEL:
|
|
|
|
/*
|
|
* Turn on/off kernel discipline
|
|
*/
|
|
kern_enable = (int)value;
|
|
break;
|
|
|
|
case PROTO_NTP:
|
|
|
|
/*
|
|
* Turn on/off clock discipline
|
|
*/
|
|
ntp_enable = (int)value;
|
|
break;
|
|
|
|
case PROTO_MONITOR:
|
|
|
|
/*
|
|
* Turn on/off monitoring
|
|
*/
|
|
if (value)
|
|
mon_start(MON_ON);
|
|
else
|
|
mon_stop(MON_ON);
|
|
break;
|
|
|
|
case PROTO_FILEGEN:
|
|
|
|
/*
|
|
* Turn on/off statistics
|
|
*/
|
|
stats_control = (int)value;
|
|
break;
|
|
|
|
case PROTO_BROADCLIENT:
|
|
|
|
/*
|
|
* Turn on/off facility to listen to broadcasts
|
|
*/
|
|
sys_bclient = (int)value;
|
|
if (value)
|
|
io_setbclient();
|
|
else
|
|
io_unsetbclient();
|
|
break;
|
|
|
|
case PROTO_MULTICAST_ADD:
|
|
|
|
/*
|
|
* Add muliticast group address
|
|
*/
|
|
io_multicast_add(value);
|
|
break;
|
|
|
|
case PROTO_MULTICAST_DEL:
|
|
|
|
/*
|
|
* Delete multicast group address
|
|
*/
|
|
io_multicast_del(value);
|
|
break;
|
|
|
|
case PROTO_BROADDELAY:
|
|
|
|
/*
|
|
* Set default broadcast delay
|
|
*/
|
|
sys_bdelay = dvalue;
|
|
break;
|
|
|
|
case PROTO_AUTHENTICATE:
|
|
|
|
/*
|
|
* Specify the use of authenticated data
|
|
*/
|
|
sys_authenticate = (int)value;
|
|
break;
|
|
|
|
case PROTO_PPS:
|
|
|
|
/*
|
|
* Turn on/off PPS discipline
|
|
*/
|
|
pps_enable = (int)value;
|
|
break;
|
|
|
|
#ifdef REFCLOCK
|
|
case PROTO_CAL:
|
|
|
|
/*
|
|
* Turn on/off refclock calibrate
|
|
*/
|
|
cal_enable = (int)value;
|
|
break;
|
|
#endif
|
|
|
|
default:
|
|
|
|
/*
|
|
* Log this error
|
|
*/
|
|
msyslog(LOG_ERR,
|
|
"proto_config: illegal item %d, value %ld",
|
|
item, value);
|
|
break;
|
|
}
|
|
}
|
|
|
|
|
|
/*
|
|
* proto_clr_stats - clear protocol stat counters
|
|
*/
|
|
void
|
|
proto_clr_stats(void)
|
|
{
|
|
sys_badstratum = 0;
|
|
sys_oldversionpkt = 0;
|
|
sys_newversionpkt = 0;
|
|
sys_unknownversion = 0;
|
|
sys_badlength = 0;
|
|
sys_processed = 0;
|
|
sys_badauth = 0;
|
|
sys_stattime = current_time;
|
|
sys_limitrejected = 0;
|
|
}
|