3451 lines
94 KiB
C
3451 lines
94 KiB
C
/*
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* ntp_proto.c - NTP version 4 protocol machinery
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*
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* ATTENTION: Get approval from Dave Mills on all changes to this file!
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*
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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 <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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* This macro defines the authentication state. If x is 1 authentication
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* is required; othewise it is optional.
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*/
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#define AUTH(x, y) ((x) ? (y) == AUTH_OK : (y) == AUTH_OK || \
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(y) == AUTH_NONE)
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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 (log2 s) */
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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; /* source/loop in network byte order */
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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_pps; /* our PPS peer */
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struct peer *sys_prefer; /* our cherished peer */
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int sys_kod; /* kod credit */
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int sys_kod_rate = 2; /* max kod packets per second */
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#ifdef OPENSSL
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u_long sys_automax; /* maximum session key lifetime */
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#endif /* OPENSSL */
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/*
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* Nonspecified system state variables.
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*/
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int sys_bclient; /* broadcast client enable */
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double sys_bdelay; /* broadcast client default delay */
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int sys_calldelay; /* modem callup delay (s) */
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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 double sys_mindisp = MINDISPERSE; /* min disp increment (s) */
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static double sys_maxdist = MAXDISTANCE; /* selection threshold (s) */
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double sys_jitter; /* system jitter (s) */
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static int sys_hopper; /* anticlockhop counter */
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static int sys_maxhop = MAXHOP; /* anticlockhop counter threshold */
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int leap_next; /* leap consensus */
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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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int peer_ntpdate; /* active peers in ntpdate mode */
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int sys_survivors; /* truest of the truechimers */
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#ifdef OPENSSL
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char *sys_hostname; /* gethostname() name */
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#endif /* OPENSSL */
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/*
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* TOS and multicast mapping stuff
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*/
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int sys_floor = 0; /* cluster stratum floor */
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int sys_ceiling = STRATUM_UNSPEC; /* cluster stratum ceiling */
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int sys_minsane = 1; /* minimum candidates */
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int sys_minclock = NTP_MINCLOCK; /* minimum survivors */
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int sys_maxclock = NTP_MAXCLOCK; /* maximum candidates */
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int sys_cohort = 0; /* cohort switch */
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int sys_orphan = STRATUM_UNSPEC + 1; /* orphan stratum */
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double sys_orphandelay = 0; /* orphan root delay */
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int sys_beacon = BEACON; /* manycast beacon interval */
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int sys_ttlmax; /* max ttl mapping vector index */
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u_char sys_ttl[MAX_TTL]; /* ttl mapping vector */
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/*
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* Statistics counters
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*/
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u_long sys_stattime; /* time since reset */
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u_long sys_received; /* packets received */
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u_long sys_processed; /* packets processed */
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u_long sys_newversionpkt; /* current version */
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u_long sys_oldversionpkt; /* recent version */
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u_long sys_unknownversion; /* invalid version */
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u_long sys_restricted; /* access denied */
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u_long sys_badlength; /* bad length or format */
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u_long sys_badauth; /* bad authentication */
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u_long sys_limitrejected; /* rate exceeded */
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static double root_distance P((struct peer *));
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static void 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,
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int));
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static void clock_update P((void));
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static int default_get_precision P((void));
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static int peer_unfit P((struct peer *));
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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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/*
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* The polling state machine. There are two kinds of machines,
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* those that never expect a reply (broadcast and manycast
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* server modes) and those that do (all other modes). The dance
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* is intricate...
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*/
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/*
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* Orphan mode is active when enabled and when no servers less
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* than the orphan statum are available. In this mode packets
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* are sent at the orphan stratum. An orphan with no other
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* synchronization source is an orphan parent. It assumes root
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* delay zero and reference ID the loopback address. All others
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* are orphan children with root delay randomized over a 1-s
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* range. The root delay is used by the election algorithm to
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* select the order of synchronization.
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*/
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hpoll = peer->hpoll;
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if (sys_orphan < STRATUM_UNSPEC && sys_peer == NULL) {
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sys_leap = LEAP_NOWARNING;
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sys_stratum = sys_orphan;
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sys_refid = htonl(LOOPBACKADR);
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sys_rootdelay = 0;
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sys_rootdispersion = 0;
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}
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/*
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* In broadcast mode the poll interval is never changed from
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* minpoll.
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*/
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if (peer->cast_flags & (MDF_BCAST | MDF_MCAST)) {
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peer->outdate = current_time;
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peer_xmit(peer);
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poll_update(peer, hpoll);
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return;
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}
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/*
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* In manycast mode we start with unity ttl. The ttl is
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* increased by one for each poll until either sys_maxclock
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* servers have been found or the maximum ttl is reached. When
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* sys_maxclock servers are found we stop polling until one or
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* more servers have timed out or until less than minpoll
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* associations turn up. In this case additional better servers
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* are dragged in and preempt the existing ones.
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*/
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if (peer->cast_flags & MDF_ACAST) {
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peer->outdate = current_time;
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if (peer->unreach > sys_beacon) {
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peer->unreach = 0;
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peer->ttl = 0;
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peer_xmit(peer);
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} else if (sys_survivors < sys_minclock ||
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peer_preempt < sys_maxclock) {
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if (peer->ttl < sys_ttlmax)
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peer->ttl++;
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peer_xmit(peer);
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}
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peer->unreach++;
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poll_update(peer, hpoll);
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return;
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}
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/*
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* In unicast modes the dance is much more intricate. It is
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* desigmed to back off whenever possible to minimize network
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* traffic.
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*/
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if (peer->burst == 0) {
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u_char oreach;
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/*
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* Update the reachability status. If not heard for
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* three consecutive polls, stuff infinity in the clock
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* filter.
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*/
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oreach = peer->reach;
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peer->outdate = current_time;
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if (peer == sys_peer)
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sys_hopper++;
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peer->reach <<= 1;
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if (!(peer->reach & 0x07))
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clock_filter(peer, 0., 0., MAXDISPERSE);
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if (!peer->reach) {
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/*
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* Here the peer is unreachable. If it was
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* previously reachable, raise a trap.
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*/
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if (oreach) {
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report_event(EVNT_UNREACH, peer);
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peer->timereachable = current_time;
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}
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/*
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* Send a burst if enabled, but only once after
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* a peer becomes unreachable. If the prempt
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* flag is dim, bump the unreach counter by one;
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* otherwise, bump it by three.
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*/
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if (peer->flags & FLAG_IBURST &&
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peer->unreach == 0) {
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peer->burst = NTP_BURST;
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}
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if (!(peer->flags & FLAG_PREEMPT))
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peer->unreach++;
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else
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peer->unreach += 3;
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} else {
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/*
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* Here the peer is reachable. Set the poll
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* interval to the system poll interval. Send a
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* burst only if enabled and the peer is fit.
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*
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* Respond to the peer evaluation produced by
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* the selection algorithm. If less than the
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* outlyer level, up the unreach by three. If
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* there are excess associations, up the unreach
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* by two if not a candidate and by one if so.
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*/
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if (!(peer->flags & FLAG_PREEMPT)) {
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peer->unreach = 0;
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} else if (peer->status < CTL_PST_SEL_SELCAND) {
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peer->unreach += 3;
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} else if (peer_preempt > sys_maxclock) {
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if (peer->status < CTL_PST_SEL_SYNCCAND)
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peer->unreach += 2;
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else
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peer->unreach++;
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} else {
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peer->unreach = 0;
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}
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hpoll = sys_poll;
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if (peer->flags & FLAG_BURST &&
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!peer_unfit(peer))
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peer->burst = NTP_BURST;
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}
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/*
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* Watch for timeout. If ephemeral or preemptable, toss
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* the rascal; otherwise, bump the poll interval.
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*/
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if (peer->unreach >= NTP_UNREACH) {
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if (peer->flags & FLAG_PREEMPT ||
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!(peer->flags & FLAG_CONFIG)) {
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peer_clear(peer, "TIME");
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unpeer(peer);
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return;
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} else {
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hpoll++;
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}
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}
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} else {
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peer->burst--;
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/*
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* If a broadcast client at this point, the burst has
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* concluded, so we switch to client mode and purge the
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* keylist, since no further transmissions will be made.
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*/
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if (peer->burst == 0) {
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if (peer->cast_flags & MDF_BCLNT) {
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peer->hmode = MODE_BCLIENT;
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#ifdef OPENSSL
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key_expire(peer);
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#endif /* OPENSSL */
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}
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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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msyslog(LOG_NOTICE,
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"no reply; clock not set");
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exit (0);
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}
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}
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}
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}
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/*
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* Do not transmit if in broadcast client mode.
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*/
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if (peer->hmode != MODE_BCLIENT)
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peer_xmit(peer);
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poll_update(peer, hpoll);
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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; /* peer structure pointer */
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register struct pkt *pkt; /* receive packet pointer */
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int hisversion; /* packet version */
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int hisleap; /* packet leap indicator */
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int hismode; /* packet mode */
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int hisstratum; /* packet stratum */
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int restrict_mask; /* restrict bits */
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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 = 0; /* cryptosum ok */
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keyid_t skeyid = 0; /* key ID */
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struct sockaddr_storage *dstadr_sin; /* active runway */
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struct peer *peer2; /* aux peer structure pointer */
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l_fp p_org; /* origin timestamp */
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l_fp p_rec; /* receive timestamp */
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l_fp p_xmt; /* transmit timestamp */
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#ifdef OPENSSL
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keyid_t tkeyid = 0; /* temporary key ID */
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keyid_t pkeyid = 0; /* previous key ID */
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struct autokey *ap; /* autokey structure pointer */
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int rval; /* cookie snatcher */
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#endif /* OPENSSL */
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int retcode = AM_NOMATCH;
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int at_listhead;
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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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/*
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* Bogus port check is before anything, since it probably
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* reveals a clogging attack.
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*/
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sys_received++;
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if (SRCPORT(&rbufp->recv_srcadr) == 0) {
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sys_badlength++;
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return; /* bogus port */
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}
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at_listhead = ntp_monitor(rbufp);
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restrict_mask = restrictions(&rbufp->recv_srcadr, at_listhead);
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#ifdef DEBUG
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if (debug > 1)
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printf("receive: at %ld %s<-%s flags %x restrict %03x\n",
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current_time, stoa(&rbufp->dstadr->sin),
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stoa(&rbufp->recv_srcadr),
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rbufp->dstadr->flags, restrict_mask);
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#endif
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if (restrict_mask & RES_IGNORE) {
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sys_restricted++;
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return; /* ignore everything */
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}
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pkt = &rbufp->recv_pkt;
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hisversion = PKT_VERSION(pkt->li_vn_mode);
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hisleap = PKT_LEAP(pkt->li_vn_mode);
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hismode = (int)PKT_MODE(pkt->li_vn_mode);
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hisstratum = PKT_TO_STRATUM(pkt->stratum);
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if (hismode == MODE_PRIVATE) {
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if (restrict_mask & RES_NOQUERY) {
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sys_restricted++;
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return; /* no query private */
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}
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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 (hismode == MODE_CONTROL) {
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if (restrict_mask & RES_NOQUERY) {
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sys_restricted++;
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return; /* no query control */
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}
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process_control(rbufp, restrict_mask);
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return;
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}
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if (restrict_mask & RES_DONTSERVE) {
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sys_restricted++;
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return; /* no time */
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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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* Version check must be after the query packets, since they
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* intentionally use early version.
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*/
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if (hisversion == NTP_VERSION) {
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sys_newversionpkt++; /* new version */
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} else if (!(restrict_mask & RES_VERSION) && hisversion >=
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NTP_OLDVERSION) {
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sys_oldversionpkt++; /* previous version */
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} else {
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sys_unknownversion++;
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return; /* old version */
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}
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/*
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* Figure out his mode and validate the packet. This has some
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* legacy raunch that probably should be removed. In very early
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* NTP versions mode 0 was equivalent to what later versions
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* would interpret as client mode.
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*/
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if (hismode == MODE_UNSPEC) {
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if (hisversion == NTP_OLDVERSION) {
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hismode = MODE_CLIENT;
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} else {
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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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|
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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, no MAC
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* is present and the packet is not authenticated. If 1, the
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* packet is a crypto-NAK; if 3, the packet is authenticated
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* with DES; if 5, the packet is authenticated with MD5. If 2 or
|
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* 4, the packet is a runt and discarded forthwith. If greater
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* than 5, an extension field is present, so we subtract the
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* length of the field and go around again.
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*/
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authlen = LEN_PKT_NOMAC;
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has_mac = rbufp->recv_length - authlen;
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while (has_mac > 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; /* bad MAC length */
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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 > NTP_MAXEXTEN || temp % 4
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!= 0) {
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sys_badlength++;
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return; /* bad MAC length */
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}
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authlen += temp;
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has_mac -= temp;
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} else {
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sys_badlength++;
|
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return; /* bad MAC length */
|
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}
|
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}
|
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#ifdef OPENSSL
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pkeyid = tkeyid = 0;
|
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#endif /* OPENSSL */
|
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|
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/*
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* We have tossed out as many buggy packets as possible early in
|
|
* 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 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,
|
|
* the interface broadcast address is used instead.
|
|
& Notwithstanding this technobabble, if the sender is a
|
|
* multicaster, the broadcast address is null, so we use the
|
|
* unicast address anyway. Don't ask.
|
|
*/
|
|
peer = findpeer(&rbufp->recv_srcadr, rbufp->dstadr, hismode,
|
|
&retcode);
|
|
dstadr_sin = &rbufp->dstadr->sin;
|
|
NTOHL_FP(&pkt->org, &p_org);
|
|
NTOHL_FP(&pkt->rec, &p_rec);
|
|
NTOHL_FP(&pkt->xmt, &p_xmt);
|
|
|
|
/*
|
|
* Authentication is conditioned by three switches:
|
|
*
|
|
* NOPEER (RES_NOPEER) do not mobilize an association unless
|
|
* authenticated
|
|
* NOTRUST (RES_DONTTRUST) do not allow access unless
|
|
* authenticated (implies NOPEER)
|
|
* enable (sys_authenticate) master NOPEER switch, by default
|
|
* on
|
|
*
|
|
* The NOPEER and NOTRUST can be specified on a per-client basis
|
|
* using the restrict command. The enable switch if on implies
|
|
* NOPEER for all clients. There are four outcomes:
|
|
*
|
|
* NONE The packet has no MAC.
|
|
* OK the packet has a MAC and authentication succeeds
|
|
* ERROR the packet has a MAC and authentication fails
|
|
* CRYPTO crypto-NAK. The MAC has four octets only.
|
|
*
|
|
* Note: The AUTH(x, y) macro is used to filter outcomes. If x
|
|
* is zero, acceptable outcomes of y are NONE and OK. If x is
|
|
* one, the only acceptable outcome of y is OK.
|
|
*/
|
|
if (has_mac == 0) {
|
|
is_authentic = AUTH_NONE; /* not required */
|
|
#ifdef DEBUG
|
|
if (debug)
|
|
printf("receive: at %ld %s<-%s mode %d code %d auth %d\n",
|
|
current_time, stoa(dstadr_sin),
|
|
stoa(&rbufp->recv_srcadr), hismode, retcode,
|
|
is_authentic);
|
|
#endif
|
|
} else if (has_mac == 4) {
|
|
is_authentic = AUTH_CRYPTO; /* crypto-NAK */
|
|
#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, stoa(dstadr_sin),
|
|
stoa(&rbufp->recv_srcadr), hismode, retcode,
|
|
skeyid, authlen, has_mac, is_authentic);
|
|
#endif
|
|
} else {
|
|
#ifdef OPENSSL
|
|
/*
|
|
* For autokey modes, generate the session key
|
|
* and install in the key cache. Use the socket
|
|
* broadcast or unicast address as appropriate.
|
|
*/
|
|
if (skeyid > NTP_MAXKEY) {
|
|
|
|
/*
|
|
* More on the autokey dance (AKD). A cookie is
|
|
* constructed from public and private values.
|
|
* For broadcast packets, the cookie is public
|
|
* (zero). For packets that match no
|
|
* association, the cookie is hashed from the
|
|
* addresses and private value. For server
|
|
* packets, the cookie was previously obtained
|
|
* from the server. For symmetric modes, the
|
|
* cookie was previously constructed using an
|
|
* agreement protocol; however, should PKI be
|
|
* unavailable, we construct a fake agreement as
|
|
* the EXOR of the peer and host cookies.
|
|
*
|
|
* hismode ephemeral persistent
|
|
* =======================================
|
|
* active 0 cookie#
|
|
* passive 0% cookie#
|
|
* client sys cookie 0%
|
|
* server 0% sys cookie
|
|
* broadcast 0 0
|
|
*
|
|
* # if unsync, 0
|
|
* % can't happen
|
|
*/
|
|
if (hismode == MODE_BROADCAST) {
|
|
|
|
/*
|
|
* For broadcaster, use the interface
|
|
* broadcast address when available;
|
|
* otherwise, use the unicast address
|
|
* found when the association was
|
|
* mobilized. However, if this is from
|
|
* the wildcard interface, game over.
|
|
*/
|
|
if (crypto_flags && rbufp->dstadr ==
|
|
any_interface) {
|
|
sys_restricted++;
|
|
return; /* no wildcard */
|
|
}
|
|
pkeyid = 0;
|
|
if (!SOCKNUL(&rbufp->dstadr->bcast))
|
|
dstadr_sin =
|
|
&rbufp->dstadr->bcast;
|
|
} else if (peer == NULL) {
|
|
pkeyid = session_key(
|
|
&rbufp->recv_srcadr, dstadr_sin, 0,
|
|
sys_private, 0);
|
|
} else {
|
|
pkeyid = peer->pcookie;
|
|
}
|
|
|
|
/*
|
|
* The session key includes both the public
|
|
* values and cookie. In case of an extension
|
|
* field, the cookie used for authentication
|
|
* purposes is zero. Note the hash is saved for
|
|
* use later in the autokey mambo.
|
|
*/
|
|
if (authlen > LEN_PKT_NOMAC && pkeyid != 0) {
|
|
session_key(&rbufp->recv_srcadr,
|
|
dstadr_sin, skeyid, 0, 2);
|
|
tkeyid = session_key(
|
|
&rbufp->recv_srcadr, dstadr_sin,
|
|
skeyid, pkeyid, 0);
|
|
} else {
|
|
tkeyid = session_key(
|
|
&rbufp->recv_srcadr, dstadr_sin,
|
|
skeyid, pkeyid, 2);
|
|
}
|
|
|
|
}
|
|
#endif /* OPENSSL */
|
|
|
|
/*
|
|
* 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 the packet is authentic, it can mobilize an
|
|
* association. Note that there is no key zero.
|
|
*/
|
|
if (!authdecrypt(skeyid, (u_int32 *)pkt, authlen,
|
|
has_mac)) {
|
|
is_authentic = AUTH_ERROR;
|
|
sys_badauth++;
|
|
} else {
|
|
is_authentic = AUTH_OK;
|
|
}
|
|
#ifdef OPENSSL
|
|
if (skeyid > NTP_MAXKEY)
|
|
authtrust(skeyid, 0);
|
|
#endif /* OPENSSL */
|
|
#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, stoa(dstadr_sin),
|
|
stoa(&rbufp->recv_srcadr), hismode, retcode,
|
|
skeyid, authlen, has_mac, is_authentic);
|
|
#endif
|
|
}
|
|
|
|
/*
|
|
* The association matching rules are implemented by a set of
|
|
* routines and an association table. A packet matching an
|
|
* association is processed by the peer process for that
|
|
* association. If there are no errors, an ephemeral association
|
|
* is mobilized: a broadcast packet mobilizes a broadcast client
|
|
* aassociation; a manycast server packet mobilizes a manycast
|
|
* client association; a symmetric active packet mobilizes a
|
|
* symmetric passive association.
|
|
*/
|
|
switch (retcode) {
|
|
|
|
/*
|
|
* This is a client mode packet not matching any association. If
|
|
* an ordinary client, simply toss a server mode packet back
|
|
* over the fence. If a manycast client, we have to work a
|
|
* little harder.
|
|
*/
|
|
case AM_FXMIT:
|
|
|
|
/*
|
|
* The vanilla case is when this is not a multicast
|
|
* interface. If authentication succeeds, return a
|
|
* server mode packet; if not and the key ID is nonzero,
|
|
* return a crypto-NAK.
|
|
*/
|
|
if (!(rbufp->dstadr->flags & INT_MCASTOPEN)) {
|
|
if (AUTH(restrict_mask & RES_DONTTRUST,
|
|
is_authentic))
|
|
fast_xmit(rbufp, MODE_SERVER, skeyid,
|
|
restrict_mask);
|
|
else if (is_authentic == AUTH_ERROR)
|
|
fast_xmit(rbufp, MODE_SERVER, 0,
|
|
restrict_mask);
|
|
return; /* hooray */
|
|
}
|
|
|
|
/*
|
|
* This must be manycast. Do not respond if not
|
|
* configured as a manycast server.
|
|
*/
|
|
if (!sys_manycastserver) {
|
|
sys_restricted++;
|
|
return; /* not enabled */
|
|
}
|
|
|
|
/*
|
|
* Do not respond if unsynchronized or stratum is below
|
|
* the floor or at or above the ceiling.
|
|
*/
|
|
if (sys_leap == LEAP_NOTINSYNC || sys_stratum <
|
|
sys_floor || sys_stratum >= sys_ceiling)
|
|
return; /* bad stratum */
|
|
|
|
/*
|
|
* Do not respond if our stratum is greater than the
|
|
* manycaster or it has already synchronized to us.
|
|
*/
|
|
if (sys_peer == NULL || hisstratum < sys_stratum ||
|
|
(sys_cohort && hisstratum == sys_stratum) ||
|
|
rbufp->dstadr->addr_refid == pkt->refid)
|
|
return; /* no help */
|
|
|
|
/*
|
|
* Respond only if authentication succeeds. Don't do a
|
|
* crypto-NAK, as that would not be useful.
|
|
*/
|
|
if (AUTH(restrict_mask & RES_DONTTRUST, is_authentic))
|
|
fast_xmit(rbufp, MODE_SERVER, skeyid,
|
|
restrict_mask);
|
|
|
|
return; /* hooray */
|
|
|
|
/*
|
|
* This is a server mode packet returned in response to a client
|
|
* mode packet sent to a multicast group address. The origin
|
|
* 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.
|
|
*
|
|
* If the packet is authentic and the manycast association is
|
|
* found, we mobilize a client association and copy pertinent
|
|
* variables from the manycast association to the new client
|
|
* association. If not, just ignore the packet.
|
|
*
|
|
* There is an implosion hazard at the manycast client, since
|
|
* the manycast servers send the server packet immediately. If
|
|
* the guy is already here, don't fire up a duplicate.
|
|
*/
|
|
case AM_MANYCAST:
|
|
if (!AUTH(sys_authenticate | (restrict_mask &
|
|
(RES_NOPEER | RES_DONTTRUST)), is_authentic))
|
|
return; /* bad auth */
|
|
|
|
if ((peer2 = findmanycastpeer(rbufp)) == NULL) {
|
|
sys_restricted++;
|
|
return; /* not enabled */
|
|
}
|
|
if ((peer = newpeer(&rbufp->recv_srcadr,
|
|
rbufp->dstadr, MODE_CLIENT,
|
|
hisversion, NTP_MINDPOLL, NTP_MAXDPOLL,
|
|
FLAG_IBURST | FLAG_PREEMPT, MDF_UCAST | MDF_ACLNT,
|
|
0, skeyid)) == NULL)
|
|
return; /* system error */
|
|
|
|
/*
|
|
* We don't need these, but it warms the billboards.
|
|
*/
|
|
peer->ttl = peer2->ttl;
|
|
break;
|
|
|
|
/*
|
|
* This is the first packet received from a broadcast server. If
|
|
* the packet is authentic and we are enabled as broadcast
|
|
* client, mobilize a broadcast client association. We don't
|
|
* kiss any frogs here.
|
|
*/
|
|
case AM_NEWBCL:
|
|
if (!AUTH(sys_authenticate | (restrict_mask &
|
|
(RES_NOPEER | RES_DONTTRUST)), is_authentic))
|
|
return; /* bad auth */
|
|
|
|
/*
|
|
* Do not respond if unsynchronized or stratum is below
|
|
* the floor or at or above the ceiling.
|
|
*/
|
|
if (hisleap == LEAP_NOTINSYNC || hisstratum <
|
|
sys_floor || hisstratum >= sys_ceiling)
|
|
return; /* bad stratum */
|
|
|
|
switch (sys_bclient) {
|
|
|
|
/*
|
|
* If not enabled, just skedaddle.
|
|
*/
|
|
case 0:
|
|
sys_restricted++;
|
|
return; /* not enabled */
|
|
|
|
/*
|
|
* Execute the initial volley in order to calibrate the
|
|
* propagation delay and run the Autokey protocol, if
|
|
* enabled.
|
|
*/
|
|
case 1:
|
|
if ((peer = newpeer(&rbufp->recv_srcadr,
|
|
rbufp->dstadr, MODE_CLIENT, hisversion,
|
|
NTP_MINDPOLL, NTP_MAXDPOLL, FLAG_MCAST |
|
|
FLAG_IBURST, MDF_BCLNT, 0, skeyid)) ==
|
|
NULL)
|
|
return; /* system error */
|
|
#ifdef OPENSSL
|
|
if (skeyid > NTP_MAXKEY)
|
|
crypto_recv(peer, rbufp);
|
|
#endif /* OPENSSL */
|
|
return; /* hooray */
|
|
|
|
|
|
/*
|
|
* Do not execute the initial volley.
|
|
*/
|
|
case 2:
|
|
#ifdef OPENSSL
|
|
/*
|
|
* If a two-way exchange is not possible,
|
|
* neither is Autokey.
|
|
*/
|
|
if (skeyid > NTP_MAXKEY) {
|
|
msyslog(LOG_INFO,
|
|
"receive: autokey requires two-way communication");
|
|
return; /* no autokey */
|
|
}
|
|
#endif /* OPENSSL */
|
|
if ((peer = newpeer(&rbufp->recv_srcadr,
|
|
rbufp->dstadr, MODE_BCLIENT, hisversion,
|
|
NTP_MINDPOLL, NTP_MAXDPOLL, 0, MDF_BCLNT, 0,
|
|
skeyid)) == NULL)
|
|
return; /* system error */
|
|
}
|
|
break;
|
|
|
|
/*
|
|
* This is the first packet received from a symmetric active
|
|
* peer. If the packet is authentic and the first he sent,
|
|
* mobilize a passive association. If not, kiss the frog.
|
|
*/
|
|
case AM_NEWPASS:
|
|
|
|
/*
|
|
* If the inbound packet is correctly authenticated and
|
|
* enabled, a symmetric passive association is
|
|
* mobilized. If not but correctly authenticated, a
|
|
* symmetric active response is sent. If authentication
|
|
* fails, send a crypto-NAK packet.
|
|
*/
|
|
if (!AUTH(restrict_mask & RES_DONTTRUST, is_authentic))
|
|
{
|
|
if (is_authentic == AUTH_ERROR)
|
|
fast_xmit(rbufp, MODE_ACTIVE, 0,
|
|
restrict_mask);
|
|
return; /* bad auth */
|
|
}
|
|
if (!AUTH(sys_authenticate | (restrict_mask &
|
|
RES_NOPEER), is_authentic)) {
|
|
fast_xmit(rbufp, MODE_ACTIVE, skeyid,
|
|
restrict_mask);
|
|
return; /* hooray */
|
|
}
|
|
|
|
/*
|
|
* Do not respond if stratum is below the floor.
|
|
*/
|
|
if (hisstratum < sys_floor)
|
|
return; /* bad stratum */
|
|
|
|
if ((peer = newpeer(&rbufp->recv_srcadr,
|
|
rbufp->dstadr, MODE_PASSIVE, hisversion,
|
|
NTP_MINDPOLL, NTP_MAXDPOLL, 0, MDF_UCAST, 0,
|
|
skeyid)) == NULL)
|
|
return; /* system error */
|
|
break;
|
|
|
|
/*
|
|
* Process regular packet. Nothing special.
|
|
*/
|
|
case AM_PROCPKT:
|
|
break;
|
|
|
|
/*
|
|
* A passive packet matches a passive association. This is
|
|
* usually the result of reconfiguring a client on the fly. As
|
|
* this association might be legitamate and this packet an
|
|
* attempt to deny service, just ignore it.
|
|
*/
|
|
case AM_ERR:
|
|
return;
|
|
|
|
/*
|
|
* For everything else there is the bit bucket.
|
|
*/
|
|
default:
|
|
return;
|
|
}
|
|
peer->flash &= ~PKT_TEST_MASK;
|
|
|
|
/*
|
|
* Next comes a rigorous schedule of timestamp checking. If the
|
|
* transmit timestamp is zero, the server is horribly broken.
|
|
*/
|
|
if (L_ISZERO(&p_xmt)) {
|
|
return; /* read rfc1305 */
|
|
|
|
/*
|
|
* If the transmit timestamp duplicates a previous one, the
|
|
* packet is a replay. This prevents the bad guys from replaying
|
|
* the most recent packet, authenticated or not.
|
|
*/
|
|
} else if (L_ISEQU(&peer->org, &p_xmt)) {
|
|
peer->flash |= TEST1;
|
|
peer->oldpkt++;
|
|
return; /* duplicate packet */
|
|
|
|
|
|
/*
|
|
* If this is a broadcast mode packet, skip further checking.
|
|
*/
|
|
} else if (hismode != MODE_BROADCAST) {
|
|
if (L_ISZERO(&p_org))
|
|
peer->flash |= TEST3; /* protocol unsynch */
|
|
else if (!L_ISEQU(&p_org, &peer->xmt))
|
|
peer->flash |= TEST2; /* bogus packet */
|
|
}
|
|
|
|
/*
|
|
* Update the origin and destination timestamps. If
|
|
* unsynchronized or bogus abandon ship. If the crypto machine
|
|
* breaks, light the crypto bit and plaint the log.
|
|
*/
|
|
peer->org = p_xmt;
|
|
peer->rec = rbufp->recv_time;
|
|
if (peer->flash & PKT_TEST_MASK) {
|
|
#ifdef OPENSSL
|
|
if (crypto_flags && (peer->flags & FLAG_SKEY)) {
|
|
rval = crypto_recv(peer, rbufp);
|
|
if (rval != XEVNT_OK) {
|
|
peer_clear(peer, "CRYP");
|
|
peer->flash |= TEST9; /* crypto error */
|
|
}
|
|
}
|
|
#endif /* OPENSSL */
|
|
return; /* unsynch */
|
|
}
|
|
|
|
/*
|
|
* The timestamps are valid and the receive packet matches the
|
|
* last one sent. If the packet is a crypto-NAK, the server
|
|
* might have just changed keys. We reset the association
|
|
* and restart the protocol.
|
|
*/
|
|
if (is_authentic == AUTH_CRYPTO) {
|
|
peer_clear(peer, "AUTH");
|
|
return; /* crypto-NAK */
|
|
|
|
/*
|
|
* If the association is authenticated, the key ID is nonzero
|
|
* and received packets must be authenticated. This is designed
|
|
* to avoid a bait-and-switch attack, which was possible in past
|
|
* versions. If symmetric modes, return a crypto-NAK. The peer
|
|
* should restart the protocol.
|
|
*/
|
|
} else if (!AUTH(peer->keyid || (restrict_mask & RES_DONTTRUST),
|
|
is_authentic)) {
|
|
peer->flash |= TEST5;
|
|
if (hismode == MODE_ACTIVE || hismode == MODE_PASSIVE)
|
|
fast_xmit(rbufp, MODE_ACTIVE, 0, restrict_mask);
|
|
return; /* bad auth */
|
|
}
|
|
|
|
/*
|
|
* That was hard and I am sweaty, but the packet is squeaky
|
|
* clean. Get on with real work.
|
|
*/
|
|
peer->received++;
|
|
peer->timereceived = current_time;
|
|
if (is_authentic == AUTH_OK)
|
|
peer->flags |= FLAG_AUTHENTIC;
|
|
else
|
|
peer->flags &= ~FLAG_AUTHENTIC;
|
|
#ifdef OPENSSL
|
|
/*
|
|
* 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 this packet is in response to the one just previously
|
|
* sent or from a broadcast server, do the extension fields.
|
|
* Otherwise, assume bogosity and bail out.
|
|
*
|
|
* 3. If an extension field contains a verified signature, it is
|
|
* self-authenticated and we sit the dance.
|
|
*
|
|
* 4. If this is a server reply, check only to see that the
|
|
* transmitted key ID matches the received key ID.
|
|
*
|
|
* 5. 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.
|
|
*
|
|
* In case of crypto error, fire the orchestra and stop dancing.
|
|
* This is considered a permanant error, so light the crypto bit
|
|
* to suppress further requests. If preemptable or ephemeral,
|
|
* scuttle the ship.
|
|
*/
|
|
if (crypto_flags && (peer->flags & FLAG_SKEY)) {
|
|
peer->flash |= TEST8;
|
|
rval = crypto_recv(peer, rbufp);
|
|
if (rval != XEVNT_OK) {
|
|
peer_clear(peer, "CRYP");
|
|
peer->flash |= TEST9; /* crypto error */
|
|
if (peer->flags & FLAG_PREEMPT ||
|
|
!(peer->flags & FLAG_CONFIG))
|
|
unpeer(peer);
|
|
return;
|
|
|
|
} else if (hismode == MODE_SERVER) {
|
|
if (skeyid == peer->keyid)
|
|
peer->flash &= ~TEST8;
|
|
} else if (!(peer->flash & TEST8)) {
|
|
peer->pkeyid = skeyid;
|
|
} else if ((ap = (struct autokey *)peer->recval.ptr) !=
|
|
NULL) {
|
|
int i;
|
|
|
|
for (i = 0; ; i++) {
|
|
if (tkeyid == peer->pkeyid ||
|
|
tkeyid == ap->key) {
|
|
peer->flash &= ~TEST8;
|
|
peer->pkeyid = skeyid;
|
|
break;
|
|
}
|
|
if (i > ap->seq)
|
|
break;
|
|
tkeyid = session_key(
|
|
&rbufp->recv_srcadr, dstadr_sin,
|
|
tkeyid, pkeyid, 0);
|
|
}
|
|
}
|
|
if (!(peer->crypto & CRYPTO_FLAG_PROV)) /* test 9 */
|
|
peer->flash |= TEST8; /* not proventic */
|
|
|
|
/*
|
|
* If the transmit queue is nonempty, clamp the host
|
|
* poll interval to the packet poll interval.
|
|
*/
|
|
if (peer->cmmd != 0) {
|
|
peer->ppoll = pkt->ppoll;
|
|
poll_update(peer, peer->hpoll);
|
|
}
|
|
}
|
|
#endif /* OPENSSL */
|
|
|
|
/*
|
|
* The dance is complete and the flash bits have been lit. Toss
|
|
* the packet over the fence for processing, which may light up
|
|
* more flashers.
|
|
*/
|
|
process_packet(peer, pkt);
|
|
|
|
/*
|
|
* Well, that was nice. If TEST4 is lit, either the crypto
|
|
* machine jammed or a kiss-o'-death packet flew in, either of
|
|
* which is fatal.
|
|
*/
|
|
if (peer->flash & TEST4) {
|
|
msyslog(LOG_INFO, "receive: fatal error %04x for %s",
|
|
peer->flash, stoa(&peer->srcadr));
|
|
return;
|
|
}
|
|
}
|
|
|
|
|
|
/*
|
|
* 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
|
|
)
|
|
{
|
|
double t34, t21;
|
|
double p_offset, p_del, p_disp;
|
|
l_fp p_rec, p_xmt, p_org, p_reftime;
|
|
l_fp ci;
|
|
u_char pmode, pleap, pstratum;
|
|
|
|
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);
|
|
pmode = PKT_MODE(pkt->li_vn_mode);
|
|
pleap = PKT_LEAP(pkt->li_vn_mode);
|
|
if (pmode != MODE_BROADCAST)
|
|
NTOHL_FP(&pkt->org, &p_org);
|
|
else
|
|
p_org = peer->rec;
|
|
pstratum = PKT_TO_STRATUM(pkt->stratum);
|
|
|
|
/*
|
|
* Test for kiss-o'death packet)
|
|
*/
|
|
if (pleap == LEAP_NOTINSYNC && pstratum == STRATUM_UNSPEC) {
|
|
if (memcmp(&pkt->refid, "DENY", 4) == 0) {
|
|
peer_clear(peer, "DENY");
|
|
peer->flash |= TEST4; /* access denied */
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Capture the header values.
|
|
*/
|
|
record_raw_stats(&peer->srcadr, peer->dstadr ? &peer->dstadr->sin : NULL, &p_org,
|
|
&p_rec, &p_xmt, &peer->rec);
|
|
peer->leap = pleap;
|
|
peer->stratum = min(pstratum, STRATUM_UNSPEC);
|
|
peer->pmode = pmode;
|
|
peer->ppoll = pkt->ppoll;
|
|
peer->precision = pkt->precision;
|
|
peer->rootdelay = p_del;
|
|
peer->rootdispersion = p_disp;
|
|
peer->refid = pkt->refid; /* network byte order */
|
|
peer->reftime = p_reftime;
|
|
|
|
/*
|
|
* Verify the server is synchronized; that is, the leap bits and
|
|
* stratum are valid, the root delay and root dispersion are
|
|
* valid and the reference timestamp is not later than the
|
|
* transmit timestamp.
|
|
*/
|
|
if (pleap == LEAP_NOTINSYNC || /* test 6 */
|
|
pstratum < sys_floor || pstratum >= sys_ceiling)
|
|
peer->flash |= TEST6; /* peer not synch */
|
|
if (p_del < 0 || p_disp < 0 || p_del / /* test 7 */
|
|
2 + p_disp >= MAXDISPERSE || !L_ISHIS(&p_xmt, &p_reftime))
|
|
peer->flash |= TEST7; /* bad header */
|
|
|
|
/*
|
|
* If any tests fail at this point, the packet is discarded.
|
|
* Note that some flashers may have already been set in the
|
|
* receive() routine.
|
|
*/
|
|
if (peer->flash & PKT_TEST_MASK) {
|
|
#ifdef DEBUG
|
|
if (debug)
|
|
printf("packet: flash header %04x\n",
|
|
peer->flash);
|
|
#endif
|
|
return;
|
|
}
|
|
if (!(peer->reach)) {
|
|
report_event(EVNT_REACH, peer);
|
|
peer->timereachable = current_time;
|
|
}
|
|
poll_update(peer, peer->hpoll);
|
|
peer->reach |= 1;
|
|
|
|
/*
|
|
* For a client/server association, calculate the clock offset,
|
|
* roundtrip delay and dispersion. The equations are reordered
|
|
* from the spec for more efficient use of temporaries. For a
|
|
* broadcast association, offset the last measurement by the
|
|
* computed delay during the client/server volley. Note that
|
|
* 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 origin time.
|
|
*
|
|
* It is very important to respect the hazards of overflow. The
|
|
* only permitted operation on raw timestamps is subtraction,
|
|
* where the result is a signed quantity spanning from 68 years
|
|
* in the past to 68 years in the future. To avoid loss of
|
|
* precision, these calculations are done using 64-bit integer
|
|
* arithmetic. However, the offset and delay calculations are
|
|
* sums and differences of these first-order differences, which
|
|
* if done using 64-bit integer arithmetic, would be valid over
|
|
* only half that span. Since the typical first-order
|
|
* differences are usually very small, they are converted to 64-
|
|
* bit doubles and all remaining calculations done in floating-
|
|
* point arithmetic. This preserves the accuracy while retaining
|
|
* the 68-year span.
|
|
*
|
|
* Let t1 = p_org, t2 = p_rec, t3 = p_xmt, t4 = peer->rec:
|
|
*/
|
|
ci = p_xmt; /* t3 - t4 */
|
|
L_SUB(&ci, &peer->rec);
|
|
LFPTOD(&ci, t34);
|
|
ci = p_rec; /* t2 - t1 */
|
|
L_SUB(&ci, &p_org);
|
|
LFPTOD(&ci, t21);
|
|
ci = peer->rec; /* t4 - t1 */
|
|
L_SUB(&ci, &p_org);
|
|
|
|
/*
|
|
* 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) {
|
|
p_offset = t34;
|
|
if (peer->flags & FLAG_MCAST) {
|
|
peer->estbdelay = peer->offset - p_offset;
|
|
if (peer->hmode == MODE_CLIENT)
|
|
return;
|
|
|
|
peer->flags &= ~(FLAG_MCAST | FLAG_BURST);
|
|
}
|
|
p_offset += peer->estbdelay;
|
|
p_del = peer->delay;
|
|
p_disp = 0;
|
|
} else {
|
|
p_offset = (t21 + t34) / 2.;
|
|
p_del = t21 - t34;
|
|
LFPTOD(&ci, p_disp);
|
|
p_disp = LOGTOD(sys_precision) +
|
|
LOGTOD(peer->precision) + clock_phi * p_disp;
|
|
}
|
|
p_del = max(p_del, LOGTOD(sys_precision));
|
|
clock_filter(peer, p_offset, p_del, p_disp);
|
|
record_peer_stats(&peer->srcadr, ctlpeerstatus(peer),
|
|
peer->offset, peer->delay, peer->disp, peer->jitter);
|
|
}
|
|
|
|
|
|
/*
|
|
* clock_update - Called at system process update intervals.
|
|
*/
|
|
static void
|
|
clock_update(void)
|
|
{
|
|
u_char oleap;
|
|
u_char ostratum;
|
|
double dtemp;
|
|
|
|
/*
|
|
* There must be a system peer at this point. If we just changed
|
|
* the system peer, but have a newer sample from the old one,
|
|
* wait until newer data are available.
|
|
*/
|
|
if (sys_poll < sys_peer->minpoll)
|
|
sys_poll = sys_peer->minpoll;
|
|
if (sys_poll > sys_peer->maxpoll)
|
|
sys_poll = sys_peer->maxpoll;
|
|
poll_update(sys_peer, sys_poll);
|
|
if (sys_peer->epoch <= sys_clocktime)
|
|
return;
|
|
|
|
#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)) {
|
|
|
|
/*
|
|
* Clock exceeds panic threshold. Life as we know it ends.
|
|
*/
|
|
case -1:
|
|
report_event(EVNT_SYSFAULT, NULL);
|
|
exit (-1);
|
|
/* not reached */
|
|
|
|
/*
|
|
* Clock was stepped. Flush all time values of all peers.
|
|
*/
|
|
case 2:
|
|
clear_all();
|
|
sys_leap = LEAP_NOTINSYNC;
|
|
sys_stratum = STRATUM_UNSPEC;
|
|
sys_peer = NULL;
|
|
sys_rootdelay = 0;
|
|
sys_rootdispersion = 0;
|
|
memcpy(&sys_refid, "STEP", 4);
|
|
report_event(EVNT_CLOCKRESET, NULL);
|
|
break;
|
|
|
|
/*
|
|
* Clock was slewed. Update the system stratum, leap bits, root
|
|
* delay, root dispersion, reference ID and reference time. If
|
|
* the leap changes, we gotta reroll the keys. Except for
|
|
* reference clocks, the minimum dispersion increment is not
|
|
* less than sys_mindisp.
|
|
*/
|
|
case 1:
|
|
sys_leap = leap_next;
|
|
sys_stratum = min(sys_peer->stratum + 1,
|
|
STRATUM_UNSPEC);
|
|
sys_reftime = sys_peer->rec;
|
|
|
|
/*
|
|
* In orphan mode the stratum defaults to the orphan
|
|
* stratum. The root delay is set to a random value
|
|
* generated at startup. The root dispersion is set from
|
|
* the peer dispersion; the peer root dispersion is
|
|
* ignored.
|
|
*/
|
|
dtemp = sys_peer->disp + clock_phi * (current_time -
|
|
sys_peer->update) + sys_jitter +
|
|
fabs(sys_peer->offset);
|
|
#ifdef REFCLOCK
|
|
if (!(sys_peer->flags & FLAG_REFCLOCK) && dtemp <
|
|
sys_mindisp)
|
|
dtemp = sys_mindisp;
|
|
#else
|
|
if (dtemp < sys_mindisp)
|
|
dtemp = sys_mindisp;
|
|
#endif /* REFCLOCK */
|
|
if (sys_stratum >= sys_orphan) {
|
|
sys_stratum = sys_orphan;
|
|
sys_rootdelay = sys_peer->delay;
|
|
sys_rootdispersion = dtemp;
|
|
} else {
|
|
sys_rootdelay = sys_peer->delay +
|
|
sys_peer->rootdelay;
|
|
sys_rootdispersion = dtemp +
|
|
sys_peer->rootdispersion;
|
|
}
|
|
if (oleap == LEAP_NOTINSYNC) {
|
|
report_event(EVNT_SYNCCHG, NULL);
|
|
#ifdef OPENSSL
|
|
expire_all();
|
|
crypto_update();
|
|
#endif /* OPENSSL */
|
|
}
|
|
break;
|
|
/*
|
|
* Popcorn spike or step threshold exceeded. Pretend it never
|
|
* happened.
|
|
*/
|
|
default:
|
|
break;
|
|
}
|
|
if (ostratum != sys_stratum)
|
|
report_event(EVNT_PEERSTCHG, NULL);
|
|
}
|
|
|
|
|
|
/*
|
|
* poll_update - update peer poll interval
|
|
*/
|
|
void
|
|
poll_update(
|
|
struct peer *peer,
|
|
int mpoll
|
|
)
|
|
{
|
|
int hpoll;
|
|
|
|
/*
|
|
* This routine figures out when the next poll should be sent.
|
|
* That turns out to be wickedly complicated. The big problem is
|
|
* that sometimes the time for the next poll is in the past.
|
|
* Watch out for races here between the receive process and the
|
|
* poll process. The key assertion is that, if nextdate equals
|
|
* current_time, the call is from the poll process; otherwise,
|
|
* it is from the receive process.
|
|
*
|
|
* First, bracket the poll interval according to the type of
|
|
* association and options. If a fixed interval is configured,
|
|
* use minpoll. This primarily is for reference clocks, but
|
|
* works for any association.
|
|
*/
|
|
if (peer->flags & FLAG_FIXPOLL) {
|
|
hpoll = peer->minpoll;
|
|
|
|
/*
|
|
* The ordinary case; clamp the poll interval between minpoll
|
|
* and maxpoll.
|
|
*/
|
|
} else {
|
|
hpoll = max(min(peer->maxpoll, mpoll), peer->minpoll);
|
|
}
|
|
#ifdef OPENSSL
|
|
/*
|
|
* 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 (hpoll != peer->hpoll)
|
|
key_expire(peer);
|
|
#endif /* OPENSSL */
|
|
peer->hpoll = hpoll;
|
|
|
|
/*
|
|
* Now we figure out if there is an override. If during the
|
|
* crypto protocol and a message is pending, make it wait not
|
|
* more than two seconds.
|
|
*/
|
|
#ifdef OPENSSL
|
|
if (peer->cmmd != NULL && (sys_leap != LEAP_NOTINSYNC ||
|
|
peer->crypto)) {
|
|
peer->nextdate = current_time + RESP_DELAY;
|
|
|
|
/*
|
|
* If we get called from the receive routine while a burst is
|
|
* pending, just slink away. If from the poll routine and a
|
|
* reference clock or a pending crypto response, delay for one
|
|
* second. If this is the first sent in a burst, wait for the
|
|
* modem to come up. For others in the burst, delay two seconds.
|
|
*/
|
|
} else if (peer->burst > 0) {
|
|
#else /* OPENSSL */
|
|
if (peer->burst > 0) {
|
|
#endif /* OPENSSL */
|
|
if (peer->nextdate != current_time)
|
|
return;
|
|
#ifdef REFCLOCK
|
|
else if (peer->flags & FLAG_REFCLOCK)
|
|
peer->nextdate += RESP_DELAY;
|
|
#endif /* REFCLOCK */
|
|
else if (peer->flags & (FLAG_IBURST | FLAG_BURST) &&
|
|
peer->burst == NTP_BURST)
|
|
peer->nextdate += sys_calldelay;
|
|
else
|
|
peer->nextdate += BURST_DELAY;
|
|
/*
|
|
* The ordinary case; use the minimum of the host and peer
|
|
* intervals, but not less than minpoll. In other words,
|
|
* oversampling is okay but understampling is evil.
|
|
*/
|
|
} else {
|
|
peer->nextdate = peer->outdate +
|
|
RANDPOLL(max(min(peer->ppoll, hpoll),
|
|
peer->minpoll));
|
|
}
|
|
|
|
/*
|
|
* If the time for the next poll has already happened, bring it
|
|
* up to the next second after this one. This way the only way
|
|
* to get nexdate == current time is from the poll routine.
|
|
*/
|
|
if (peer->nextdate <= current_time)
|
|
peer->nextdate = current_time + 1;
|
|
#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->hpoll, peer->burst, peer->outdate,
|
|
peer->nextdate);
|
|
#endif
|
|
}
|
|
|
|
/*
|
|
* peer_crypto_clear - discard crypto information
|
|
*/
|
|
void
|
|
peer_crypto_clear(
|
|
struct peer *peer
|
|
)
|
|
{
|
|
/*
|
|
* 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.
|
|
*/
|
|
DPRINTF(1, ("peer_crypto_clear: at %ld next %ld assoc ID %d\n",
|
|
current_time, peer->nextdate, peer->associd));
|
|
|
|
#ifdef OPENSSL
|
|
peer->assoc = 0;
|
|
peer->crypto = 0;
|
|
|
|
if (peer->pkey != NULL)
|
|
EVP_PKEY_free(peer->pkey);
|
|
peer->pkey = NULL;
|
|
|
|
peer->digest = NULL; /* XXX MEMLEAK? check whether this needs to be freed in any way - never was freed */
|
|
|
|
if (peer->subject != NULL)
|
|
free(peer->subject);
|
|
peer->subject = NULL;
|
|
|
|
if (peer->issuer != NULL)
|
|
free(peer->issuer);
|
|
peer->issuer = NULL;
|
|
|
|
peer->pkeyid = 0;
|
|
|
|
peer->pcookie = 0;
|
|
|
|
if (peer->ident_pkey != NULL)
|
|
EVP_PKEY_free(peer->ident_pkey);
|
|
peer->ident_pkey = NULL;
|
|
|
|
memset(&peer->fstamp, 0, sizeof(peer->fstamp));
|
|
|
|
if (peer->iffval != NULL)
|
|
BN_free(peer->iffval);
|
|
peer->iffval = NULL;
|
|
|
|
if (peer->grpkey != NULL)
|
|
BN_free(peer->grpkey);
|
|
peer->grpkey = NULL;
|
|
|
|
value_free(&peer->cookval);
|
|
value_free(&peer->recval);
|
|
|
|
if (peer->cmmd != NULL) {
|
|
free(peer->cmmd);
|
|
peer->cmmd = NULL;
|
|
}
|
|
|
|
key_expire(peer);
|
|
|
|
value_free(&peer->encrypt);
|
|
#endif /* OPENSSL */
|
|
}
|
|
|
|
/*
|
|
* peer_clear - clear peer filter registers. See Section 3.4.8 of the spec.
|
|
*/
|
|
void
|
|
peer_clear(
|
|
struct peer *peer, /* peer structure */
|
|
char *ident /* tally lights */
|
|
)
|
|
{
|
|
int i;
|
|
|
|
peer_crypto_clear(peer);
|
|
|
|
if (peer == sys_peer)
|
|
sys_peer = NULL;
|
|
|
|
/*
|
|
* Wipe the association clean and initialize the nonzero values.
|
|
*/
|
|
memset(CLEAR_TO_ZERO(peer), 0, LEN_CLEAR_TO_ZERO);
|
|
peer->estbdelay = sys_bdelay;
|
|
peer->ppoll = peer->maxpoll;
|
|
peer->hpoll = peer->minpoll;
|
|
peer->disp = MAXDISPERSE;
|
|
peer->jitter = LOGTOD(sys_precision);
|
|
for (i = 0; i < NTP_SHIFT; i++) {
|
|
peer->filter_order[i] = i;
|
|
peer->filter_disp[i] = MAXDISPERSE;
|
|
}
|
|
#ifdef REFCLOCK
|
|
if (!(peer->flags & FLAG_REFCLOCK)) {
|
|
peer->leap = LEAP_NOTINSYNC;
|
|
peer->stratum = STRATUM_UNSPEC;
|
|
memcpy(&peer->refid, ident, 4);
|
|
}
|
|
#else
|
|
peer->leap = LEAP_NOTINSYNC;
|
|
peer->stratum = STRATUM_UNSPEC;
|
|
memcpy(&peer->refid, ident, 4);
|
|
#endif /* REFCLOCK */
|
|
|
|
/*
|
|
* During initialization use the association count to spread out
|
|
* the polls at one-second intervals. Othersie, randomize over
|
|
* the minimum poll interval in order to avoid broadcast
|
|
* implosion.
|
|
*/
|
|
peer->nextdate = peer->update = peer->outdate = current_time;
|
|
if (initializing)
|
|
peer->nextdate += peer_associations;
|
|
else if (peer->hmode == MODE_PASSIVE)
|
|
peer->nextdate += RESP_DELAY;
|
|
else
|
|
peer->nextdate += (ntp_random() & ((1 << NTP_MINDPOLL) -
|
|
1));
|
|
|
|
DPRINTF(1, ("peer_clear: at %ld next %ld assoc ID %d refid %s\n",
|
|
current_time, peer->nextdate, peer->associd, ident));
|
|
}
|
|
|
|
|
|
/*
|
|
* clock_filter - add incoming clock sample to filter register and run
|
|
* the filter procedure to find the best sample.
|
|
*/
|
|
void
|
|
clock_filter(
|
|
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 */
|
|
int i, j, k, m;
|
|
double 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.
|
|
*/
|
|
j = peer->filter_nextpt;
|
|
peer->filter_offset[j] = sample_offset;
|
|
peer->filter_delay[j] = max(0, sample_delay);
|
|
peer->filter_disp[j] = sample_disp;
|
|
peer->filter_epoch[j] = current_time;
|
|
j = (j + 1) % 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] = sys_maxdist + peer->filter_disp[j];
|
|
else
|
|
dst[i] = peer->filter_delay[j];
|
|
ord[i] = j;
|
|
j++; j %= NTP_SHIFT;
|
|
}
|
|
|
|
/*
|
|
* If the clock discipline has stabilized, sort the samples in
|
|
* both lists by distance. Note, we do not displace a higher
|
|
* distance sample by a lower distance one unless lower by at
|
|
* least the precision.
|
|
*/
|
|
if (state == 4) {
|
|
for (i = 1; i < NTP_SHIFT; i++) {
|
|
for (j = 0; j < i; j++) {
|
|
if (dst[j] > dst[i] +
|
|
LOGTOD(sys_precision)) {
|
|
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 max distance, but keep at least two valid samples for
|
|
* jitter calculation.
|
|
*/
|
|
m = 0;
|
|
for (i = 0; i < NTP_SHIFT; i++) {
|
|
peer->filter_order[i] = (u_char) ord[i];
|
|
if (dst[i] >= MAXDISPERSE || (m >= 2 && dst[i] >=
|
|
sys_maxdist))
|
|
continue;
|
|
m++;
|
|
}
|
|
|
|
/*
|
|
* Compute the dispersion and jitter. The dispersion is weighted
|
|
* exponentially by NTP_FWEIGHT (0.5) so it is normalized close
|
|
* to 1.0. The jitter is the RMS differences relative to the
|
|
* lowest delay sample. If no acceptable samples remain in the
|
|
* shift register, quietly tiptoe home leaving only the
|
|
* dispersion.
|
|
*/
|
|
peer->disp = peer->jitter = 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)
|
|
peer->jitter += 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. Note the jitter must not
|
|
* be less than the precision.
|
|
*/
|
|
if (m == 0)
|
|
return;
|
|
|
|
etemp = fabs(peer->offset - peer->filter_offset[k]);
|
|
peer->offset = peer->filter_offset[k];
|
|
peer->delay = peer->filter_delay[k];
|
|
if (m > 1)
|
|
peer->jitter /= m - 1;
|
|
peer->jitter = max(SQRT(peer->jitter), LOGTOD(sys_precision));
|
|
|
|
/*
|
|
* A new sample is useful only if it is younger than the last
|
|
* one used. Note the order is FIFO if the clock discipline has
|
|
* not stabilized.
|
|
*/
|
|
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 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 (etemp > CLOCK_SGATE * peer->jitter && m > 1 &&
|
|
peer->filter_epoch[k] - peer->epoch < 2. *
|
|
ULOGTOD(sys_poll)) {
|
|
#ifdef DEBUG
|
|
if (debug)
|
|
printf("clock_filter: popcorn %.6f %.6f\n",
|
|
etemp, dtemp);
|
|
#endif
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* The mitigated sample statistics are saved for later
|
|
* processing. If not in a burst, tickle the select.
|
|
*/
|
|
peer->epoch = peer->filter_epoch[k];
|
|
#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,
|
|
peer->jitter, current_time - peer->epoch);
|
|
#endif
|
|
if (peer->burst == 0 || sys_leap == LEAP_NOTINSYNC)
|
|
clock_select();
|
|
}
|
|
|
|
|
|
/*
|
|
* clock_select - find the pick-of-the-litter clock
|
|
*
|
|
* LOCKCLOCK: If the local clock is the prefer peer, it will always be
|
|
* enabled, even if declared falseticker, (2) only the prefer peer can
|
|
* be selected as the system peer, (3) if the external source is down,
|
|
* the system leap bits are set to 11 and the stratum set to infinity.
|
|
*/
|
|
void
|
|
clock_select(void)
|
|
{
|
|
struct peer *peer;
|
|
int i, j, k, n;
|
|
int nlist, nl3;
|
|
|
|
int allow, osurv;
|
|
double d, e, f, g;
|
|
double high, low;
|
|
double synch[NTP_MAXASSOC], error[NTP_MAXASSOC];
|
|
struct peer *osys_peer;
|
|
struct peer *typeacts = NULL;
|
|
struct peer *typelocal = 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_pps = NULL;
|
|
sys_prefer = NULL;
|
|
osurv = sys_survivors;
|
|
sys_survivors = 0;
|
|
#ifdef LOCKCLOCK
|
|
sys_leap = LEAP_NOTINSYNC;
|
|
sys_stratum = STRATUM_UNSPEC;
|
|
memcpy(&sys_refid, "DOWN", 4);
|
|
#endif /* LOCKCLOCK */
|
|
nlist = 0;
|
|
for (n = 0; n < NTP_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 sys_minclock, the survivors split a million
|
|
* bucks and collectively crank the chimes.
|
|
*/
|
|
nlist = nl3 = 0; /* none yet */
|
|
for (n = 0; n < NTP_HASH_SIZE; n++) {
|
|
for (peer = peer_hash[n]; peer != NULL; peer =
|
|
peer->next) {
|
|
peer->flags &= ~FLAG_SYSPEER;
|
|
peer->status = CTL_PST_SEL_REJECT;
|
|
|
|
/*
|
|
* Leave the island immediately if the peer is
|
|
* unfit to synchronize.
|
|
*/
|
|
if (peer_unfit(peer))
|
|
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.
|
|
*/
|
|
#ifdef REFCLOCK
|
|
if (peer->refclktype == REFCLK_LOCALCLOCK
|
|
#if defined(VMS) && defined(VMS_LOCALUNIT)
|
|
/* wjm: VMS_LOCALUNIT taken seriously */
|
|
&& REFCLOCKUNIT(&peer->srcadr) !=
|
|
VMS_LOCALUNIT
|
|
#endif /* VMS && VMS_LOCALUNIT */
|
|
) {
|
|
typelocal = peer;
|
|
#ifndef LOCKCLOCK
|
|
if (!(peer->flags & FLAG_PREFER))
|
|
continue; /* no local clock */
|
|
#endif /* LOCKCLOCK */
|
|
}
|
|
if (peer->sstclktype == CTL_SST_TS_TELEPHONE) {
|
|
typeacts = peer;
|
|
if (!(peer->flags & FLAG_PREFER))
|
|
continue; /* no acts */
|
|
}
|
|
#endif /* REFCLOCK */
|
|
|
|
/*
|
|
* If we get this far, the peer can stay on the
|
|
* island, but does not yet have the immunity
|
|
* idol.
|
|
*/
|
|
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
|
|
/*
|
|
* This is the actual algorithm that cleaves the truechimers
|
|
* from the falsetickers. The original algorithm was described
|
|
* in Keith Marzullo's dissertation, but has been modified for
|
|
* better accuracy.
|
|
*
|
|
* Briefly put, we first assume there are no falsetickers, then
|
|
* scan the candidate list first from the low end upwards and
|
|
* then from the high end downwards. The scans stop when the
|
|
* number of intersections equals the number of candidates less
|
|
* the number of falsetickers. If this doesn't happen for a
|
|
* given number of falsetickers, we bump the number of
|
|
* falsetickers and try again. If the number of falsetickers
|
|
* becomes equal to or greater than half the number of
|
|
* candidates, the Albanians have won the Byzantine wars and
|
|
* correct synchronization is not possible.
|
|
*
|
|
* Here, nlist is the number of candidates and allow is the
|
|
* number of falsetickers. Upon exit, the truechimers are the
|
|
* susvivors with offsets not less than low and not greater than
|
|
* high. There may be none of them.
|
|
*/
|
|
low = 1e9;
|
|
high = -1e9;
|
|
for (allow = 0; 2 * allow < nlist; allow++) {
|
|
int found;
|
|
|
|
/*
|
|
* Bound the interval (low, high) as the largest
|
|
* interval containing points from presumed truechimers.
|
|
*/
|
|
found = 0;
|
|
n = 0;
|
|
for (i = 0; i < nl3; i++) {
|
|
low = endpoint[indx[i]].val;
|
|
n -= endpoint[indx[i]].type;
|
|
if (n >= nlist - allow)
|
|
break;
|
|
if (endpoint[indx[i]].type == 0)
|
|
found++;
|
|
}
|
|
n = 0;
|
|
for (j = nl3 - 1; j >= 0; j--) {
|
|
high = endpoint[indx[j]].val;
|
|
n += endpoint[indx[j]].type;
|
|
if (n >= nlist - allow)
|
|
break;
|
|
if (endpoint[indx[j]].type == 0)
|
|
found++;
|
|
}
|
|
|
|
/*
|
|
* If the number of candidates found outside the
|
|
* interval is greater than the number of falsetickers,
|
|
* then at least one truechimer is outside the interval,
|
|
* so go around again. This is what makes this algorithm
|
|
* different than Marzullo's.
|
|
*/
|
|
if (found > allow)
|
|
continue;
|
|
|
|
/*
|
|
* If an interval containing truechimers is found, stop.
|
|
* If not, increase the number of falsetickers and go
|
|
* around again.
|
|
*/
|
|
if (high > low)
|
|
break;
|
|
}
|
|
|
|
/*
|
|
* Clustering algorithm. Construct candidate list in order first
|
|
* by stratum then by root distance, but keep only the best
|
|
* NTP_MAXASSOC of them. Scan the list to find falsetickers, who
|
|
* leave the island immediately. The TRUE peer is always a
|
|
* truechimer. We must leave at least one peer to collect the
|
|
* million bucks. If in orphan mode, rascals found with lower
|
|
* stratum are guaranteed a seat on the bus.
|
|
*/
|
|
j = 0;
|
|
for (i = 0; i < nlist; i++) {
|
|
peer = peer_list[i];
|
|
if (nlist > 1 && (peer->offset <= low || peer->offset >=
|
|
high) && !(peer->flags & FLAG_TRUE) &&
|
|
!(sys_stratum >= sys_orphan && peer->stratum <
|
|
sys_orphan))
|
|
continue;
|
|
|
|
peer->status = CTL_PST_SEL_DISTSYSPEER;
|
|
|
|
/*
|
|
* The order metric is formed from the stratum times
|
|
* max distance (1.) plus the root distance. It strongly
|
|
* favors the lowest stratum, but a higher stratum peer
|
|
* can capture the clock if the low stratum dominant
|
|
* hasn't been heard for awhile.
|
|
*/
|
|
d = root_distance(peer) + peer->stratum * sys_maxdist;
|
|
if (j >= NTP_MAXASSOC) {
|
|
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;
|
|
|
|
/*
|
|
* 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 leave
|
|
* the island to the rats.
|
|
*/
|
|
if (nlist == 0) {
|
|
if (typeacts != 0) {
|
|
typeacts->status = CTL_PST_SEL_DISTSYSPEER;
|
|
peer_list[0] = typeacts;
|
|
nlist = 1;
|
|
} else if (typelocal != 0) {
|
|
typelocal->status = CTL_PST_SEL_DISTSYSPEER;
|
|
peer_list[0] = typelocal;
|
|
nlist = 1;
|
|
} else {
|
|
if (osys_peer != NULL) {
|
|
NLOG(NLOG_SYNCSTATUS)
|
|
msyslog(LOG_INFO,
|
|
"no servers reachable");
|
|
report_event(EVNT_PEERSTCHG, NULL);
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* We can only trust the survivors if the number of candidates
|
|
* sys_minsane is at least the number required to detect and
|
|
* cast out one falsticker. For the Byzantine agreement
|
|
* algorithm used here, that number is 4; however, the default
|
|
* sys_minsane is 1 to speed initial synchronization. Careful
|
|
* operators will tinker a higher value and use at least that
|
|
* number of synchronization sources.
|
|
*/
|
|
if (nlist < sys_minsane)
|
|
return;
|
|
|
|
for (i = 0; i < nlist; i++)
|
|
peer_list[i]->status = CTL_PST_SEL_SELCAND;
|
|
|
|
/*
|
|
* Now, vote outlyers off the island by select jitter weighted
|
|
* by root distance. Continue voting as long as there are more
|
|
* than sys_minclock survivors and the minimum select jitter is
|
|
* greater than the maximum peer jitter. Stop if we are about to
|
|
* discard a TRUE or PREFER peer, who of course has the
|
|
* immunity idol.
|
|
*/
|
|
while (1) {
|
|
d = 1e9;
|
|
e = -1e9;
|
|
f = g = 0;
|
|
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 = SQRT(f / (nlist - 1));
|
|
}
|
|
if (f * synch[i] > e) {
|
|
g = f;
|
|
e = f * synch[i];
|
|
k = i;
|
|
}
|
|
}
|
|
f = max(f, LOGTOD(sys_precision));
|
|
if (nlist <= sys_minclock || f <= d ||
|
|
peer_list[k]->flags & (FLAG_TRUE | FLAG_PREFER))
|
|
break;
|
|
#ifdef DEBUG
|
|
if (debug > 2)
|
|
printf(
|
|
"select: drop %s select %.6f jitter %.6f\n",
|
|
ntoa(&peer_list[k]->srcadr), g, d);
|
|
#endif
|
|
for (j = k + 1; j < nlist; j++) {
|
|
peer_list[j - 1] = peer_list[j];
|
|
error[j - 1] = error[j];
|
|
}
|
|
nlist--;
|
|
}
|
|
|
|
/*
|
|
* What remains is a list usually not greater than sys_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. Consider each peer in turn and OR the
|
|
* leap bits on the assumption that, if some of them honk
|
|
* nonzero bits, they must know what they are doing. Check for
|
|
* prefer and pps peers at any stratum. Note that the head of
|
|
* the list is at the lowest stratum and that unsynchronized
|
|
* peers cannot survive this far.
|
|
*/
|
|
leap_next = 0;
|
|
for (i = 0; i < nlist; i++) {
|
|
peer = peer_list[i];
|
|
sys_survivors++;
|
|
leap_next |= peer->leap;
|
|
peer->status = CTL_PST_SEL_SYNCCAND;
|
|
if (peer->flags & FLAG_PREFER)
|
|
sys_prefer = peer;
|
|
if (peer == osys_peer)
|
|
typesystem = peer;
|
|
#ifdef REFCLOCK
|
|
if (peer->refclktype == REFCLK_ATOM_PPS)
|
|
sys_pps = peer;
|
|
#endif /* REFCLOCK */
|
|
#if DEBUG
|
|
if (debug > 1)
|
|
printf("cluster: survivor %s metric %.6f\n",
|
|
ntoa(&peer_list[i]->srcadr), synch[i]);
|
|
#endif
|
|
}
|
|
|
|
/*
|
|
* Anticlockhop provision. Keep the current system peer if it is
|
|
* a survivor but not first in the list. But do that only HOPPER
|
|
* times.
|
|
*/
|
|
if (osys_peer == NULL || typesystem == NULL || typesystem ==
|
|
peer_list[0] || sys_hopper > sys_maxhop) {
|
|
typesystem = peer_list[0];
|
|
sys_hopper = 0;
|
|
} else {
|
|
peer->selbroken++;
|
|
}
|
|
|
|
/*
|
|
* Mitigation rules of the game. There are several types of
|
|
* peers that can be selected here: (1) orphan, (2) prefer peer
|
|
* (flag FLAG_PREFER) (3) pps peers (type REFCLK_ATOM_PPS), (4)
|
|
* the existing system peer, if any, and (5) the head of the
|
|
* survivor list.
|
|
*/
|
|
if (typesystem->stratum >= sys_orphan) {
|
|
|
|
/*
|
|
* If in orphan mode, choose the system peer. If the
|
|
* lowest distance, we are the orphan parent and the
|
|
* offset is zero.
|
|
*/
|
|
sys_peer = typesystem;
|
|
sys_peer->status = CTL_PST_SEL_SYSPEER;
|
|
if (sys_orphandelay < sys_peer->rootdelay) {
|
|
sys_offset = 0;
|
|
sys_refid = htonl(LOOPBACKADR);
|
|
} else {
|
|
sys_offset = sys_peer->offset;
|
|
sys_refid = addr2refid(&sys_peer->srcadr);
|
|
}
|
|
sys_jitter = LOGTOD(sys_precision);
|
|
#ifdef DEBUG
|
|
if (debug > 1)
|
|
printf("select: orphan offset %.6f\n",
|
|
sys_offset);
|
|
#endif
|
|
} else if (sys_prefer) {
|
|
|
|
/*
|
|
* If a pps peer is present, choose it; otherwise,
|
|
* choose the prefer peer.
|
|
*/
|
|
if (sys_pps) {
|
|
sys_peer = sys_pps;
|
|
sys_peer->status = CTL_PST_SEL_PPS;
|
|
sys_offset = sys_peer->offset;
|
|
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 {
|
|
sys_peer = sys_prefer;
|
|
sys_peer->status = CTL_PST_SEL_SYSPEER;
|
|
sys_offset = sys_peer->offset;
|
|
#ifdef DEBUG
|
|
if (debug > 1)
|
|
printf("select: prefer offset %.6f\n",
|
|
sys_offset);
|
|
#endif
|
|
}
|
|
if (sys_peer->stratum == STRATUM_REFCLOCK ||
|
|
sys_peer->stratum == STRATUM_UNSPEC)
|
|
sys_refid = sys_peer->refid;
|
|
else
|
|
sys_refid = addr2refid(&sys_peer->srcadr);
|
|
sys_jitter = sys_peer->jitter;
|
|
} else {
|
|
|
|
/*
|
|
* Otherwise, choose the anticlockhopper.
|
|
*/
|
|
sys_peer = typesystem;
|
|
sys_peer->status = CTL_PST_SEL_SYSPEER;
|
|
clock_combine(peer_list, nlist);
|
|
if (sys_peer->stratum == STRATUM_REFCLOCK ||
|
|
sys_peer->stratum == STRATUM_UNSPEC)
|
|
sys_refid = sys_peer->refid;
|
|
else
|
|
sys_refid = addr2refid(&sys_peer->srcadr);
|
|
sys_jitter = SQRT(SQUARE(sys_peer->jitter) +
|
|
SQUARE(sys_jitter));
|
|
#ifdef DEBUG
|
|
if (debug > 1)
|
|
printf("select: combine offset %.6f\n",
|
|
sys_offset);
|
|
#endif
|
|
}
|
|
|
|
/*
|
|
* We have found the alpha male.
|
|
*/
|
|
sys_peer->flags |= FLAG_SYSPEER;
|
|
if (osys_peer != sys_peer) {
|
|
char *src;
|
|
|
|
report_event(EVNT_PEERSTCHG, NULL);
|
|
|
|
#ifdef REFCLOCK
|
|
if (sys_peer->flags & FLAG_REFCLOCK)
|
|
src = refnumtoa(&sys_peer->srcadr);
|
|
else
|
|
#endif /* REFCLOCK */
|
|
src = ntoa(&sys_peer->srcadr);
|
|
NLOG(NLOG_SYNCSTATUS)
|
|
msyslog(LOG_INFO, "synchronized to %s, stratum %d",
|
|
src, sys_peer->stratum);
|
|
}
|
|
clock_update();
|
|
}
|
|
|
|
|
|
/*
|
|
* clock_combine - compute system offset and jitter from selected peers
|
|
*/
|
|
static void
|
|
clock_combine(
|
|
struct peer **peers, /* survivor list */
|
|
int npeers /* number of survivors */
|
|
)
|
|
{
|
|
int i;
|
|
double x, y, z, w;
|
|
|
|
y = z = w = 0;
|
|
for (i = 0; i < npeers; i++) {
|
|
x = root_distance(peers[i]);
|
|
y += 1. / x;
|
|
z += peers[i]->offset / x;
|
|
w += SQUARE(peers[i]->offset - peers[0]->offset) / x;
|
|
}
|
|
sys_offset = z / y;
|
|
sys_jitter = SQRT(w / y);
|
|
}
|
|
|
|
/*
|
|
* root_distance - compute synchronization distance from peer to root
|
|
*/
|
|
static double
|
|
root_distance(
|
|
struct peer *peer
|
|
)
|
|
{
|
|
double dist;
|
|
|
|
/*
|
|
* Careful squeak here. The value returned must be greater than
|
|
* the minimum root dispersion in order to avoid clockhop with
|
|
* highly precise reference clocks. In orphan mode lose the peer
|
|
* root delay, as that is used by the election algorithm.
|
|
*/
|
|
if (peer->stratum >= sys_orphan)
|
|
dist = 0;
|
|
else
|
|
dist = peer->rootdelay;
|
|
dist += max(sys_mindisp, dist + peer->delay) / 2 +
|
|
peer->rootdispersion + peer->disp + clock_phi *
|
|
(current_time - peer->update) + peer->jitter;
|
|
return (dist);
|
|
}
|
|
|
|
/*
|
|
* 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 = 0; /* transmit key ID */
|
|
l_fp xmt_tx;
|
|
|
|
if (!peer->dstadr) /* don't bother with peers without interface */
|
|
return;
|
|
|
|
/*
|
|
* This is deliciously complicated. There are three cases.
|
|
*
|
|
* case leap stratum refid delay dispersion
|
|
*
|
|
* normal system system system system system
|
|
* orphan child 00 orphan system orphan system
|
|
* orphan parent 00 orphan loopbk 0 0
|
|
*/
|
|
/*
|
|
* This is a normal packet. Use the system variables.
|
|
*/
|
|
if (sys_stratum < sys_orphan) {
|
|
xpkt.li_vn_mode = PKT_LI_VN_MODE(sys_leap,
|
|
peer->version, peer->hmode);
|
|
xpkt.stratum = STRATUM_TO_PKT(sys_stratum);
|
|
xpkt.refid = sys_refid;
|
|
xpkt.rootdelay = HTONS_FP(DTOFP(sys_rootdelay));
|
|
xpkt.rootdispersion =
|
|
HTONS_FP(DTOUFP(sys_rootdispersion));
|
|
|
|
/*
|
|
* This is a orphan child packet. The host is synchronized to an
|
|
* orphan parent. Show leap synchronized, orphan stratum, system
|
|
* reference ID, orphan root delay and system root dispersion.
|
|
*/
|
|
} else if (sys_peer != NULL) {
|
|
xpkt.li_vn_mode = PKT_LI_VN_MODE(LEAP_NOWARNING,
|
|
peer->version, peer->hmode);
|
|
xpkt.stratum = STRATUM_TO_PKT(sys_orphan);
|
|
xpkt.refid = htonl(LOOPBACKADR);
|
|
xpkt.rootdelay = HTONS_FP(DTOFP(sys_orphandelay));
|
|
xpkt.rootdispersion =
|
|
HTONS_FP(DTOUFP(sys_rootdispersion));
|
|
|
|
/*
|
|
* This is an orphan parent. Show leap synchronized, orphan
|
|
* stratum, loopack reference ID and zero root delay and root
|
|
* dispersion.
|
|
*/
|
|
} else {
|
|
xpkt.li_vn_mode = PKT_LI_VN_MODE(LEAP_NOWARNING,
|
|
peer->version, peer->hmode);
|
|
xpkt.stratum = STRATUM_TO_PKT(sys_orphan);
|
|
xpkt.refid = sys_refid;
|
|
xpkt.rootdelay = 0;
|
|
xpkt.rootdispersion = 0;
|
|
}
|
|
xpkt.ppoll = peer->hpoll;
|
|
xpkt.precision = sys_precision;
|
|
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.
|
|
*
|
|
* It is most important when autokey is in use that the local
|
|
* interface IP address be known before the first packet is
|
|
* sent. Otherwise, it is not possible to compute a correct MAC
|
|
* the recipient will accept. Thus, the I/O semantics have to do
|
|
* a little more work. In particular, the wildcard interface
|
|
* might not be usable.
|
|
*/
|
|
sendlen = LEN_PKT_NOMAC;
|
|
if (!(peer->flags & FLAG_AUTHENABLE)) {
|
|
get_systime(&peer->xmt);
|
|
HTONL_FP(&peer->xmt, &xpkt.xmt);
|
|
sendpkt(&peer->srcadr, peer->dstadr, sys_ttl[peer->ttl],
|
|
&xpkt, sendlen);
|
|
peer->sent++;
|
|
#ifdef DEBUG
|
|
if (debug)
|
|
printf("transmit: at %ld %s->%s mode %d\n",
|
|
current_time, peer->dstadr ? stoa(&peer->dstadr->sin) : "-",
|
|
stoa(&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, symmetric key cryptography is used.
|
|
*/
|
|
#ifdef OPENSSL
|
|
if (crypto_flags && (peer->flags & FLAG_SKEY)) {
|
|
struct exten *exten; /* extension field */
|
|
|
|
/*
|
|
* 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;
|
|
exten = NULL;
|
|
switch (peer->hmode) {
|
|
|
|
/*
|
|
* In broadcast server mode the autokey values are
|
|
* required by the broadcast clients. Push them when a
|
|
* new keylist is generated; otherwise, push the
|
|
* association message so the client can request them at
|
|
* other times.
|
|
*/
|
|
case MODE_BROADCAST:
|
|
if (peer->flags & FLAG_ASSOC)
|
|
exten = crypto_args(peer, CRYPTO_AUTO |
|
|
CRYPTO_RESP, NULL);
|
|
else
|
|
exten = crypto_args(peer, CRYPTO_ASSOC |
|
|
CRYPTO_RESP, NULL);
|
|
break;
|
|
|
|
/*
|
|
* In symmetric modes the digest, certificate, agreement
|
|
* parameters, cookie and autokey values are required.
|
|
* The leapsecond table is optional. But, a passive peer
|
|
* will not believe the active peer until the latter has
|
|
* synchronized, so the agreement must be postponed
|
|
* until then. In any case, if a new keylist is
|
|
* generated, the autokey values are pushed.
|
|
*
|
|
* If the crypto bit is lit, don't send requests.
|
|
*/
|
|
case MODE_ACTIVE:
|
|
case MODE_PASSIVE:
|
|
if (peer->flash & TEST9)
|
|
break;
|
|
/*
|
|
* Parameter and certificate.
|
|
*/
|
|
if (!peer->crypto)
|
|
exten = crypto_args(peer, CRYPTO_ASSOC,
|
|
sys_hostname);
|
|
else if (!(peer->crypto & CRYPTO_FLAG_VALID))
|
|
exten = crypto_args(peer, CRYPTO_CERT,
|
|
peer->issuer);
|
|
|
|
/*
|
|
* Identity. Note we have to sign the
|
|
* certificate before the cookie to avoid a
|
|
* deadlock when the passive peer is walking the
|
|
* certificate trail. Awesome.
|
|
*/
|
|
else if (!(peer->crypto & CRYPTO_FLAG_VRFY))
|
|
exten = crypto_args(peer,
|
|
crypto_ident(peer), NULL);
|
|
else if (sys_leap != LEAP_NOTINSYNC &&
|
|
!(peer->crypto & CRYPTO_FLAG_SIGN))
|
|
exten = crypto_args(peer, CRYPTO_SIGN,
|
|
sys_hostname);
|
|
|
|
/*
|
|
* Autokey. We request the cookie only when the
|
|
* server and client are synchronized and
|
|
* signatures work both ways. On the other hand,
|
|
* the active peer needs the autokey values
|
|
* before then and when the passive peer is
|
|
* waiting for the active peer to synchronize.
|
|
* Any time we regenerate the key list, we offer
|
|
* the autokey values without being asked.
|
|
*/
|
|
else if (sys_leap != LEAP_NOTINSYNC &&
|
|
peer->leap != LEAP_NOTINSYNC &&
|
|
!(peer->crypto & CRYPTO_FLAG_AGREE))
|
|
exten = crypto_args(peer, CRYPTO_COOK,
|
|
NULL);
|
|
else if (peer->flags & FLAG_ASSOC)
|
|
exten = crypto_args(peer, CRYPTO_AUTO |
|
|
CRYPTO_RESP, NULL);
|
|
else if (!(peer->crypto & CRYPTO_FLAG_AUTO))
|
|
exten = crypto_args(peer, CRYPTO_AUTO,
|
|
NULL);
|
|
|
|
/*
|
|
* Postamble. We trade leapseconds only when the
|
|
* server and client are synchronized.
|
|
*/
|
|
else if (sys_leap != LEAP_NOTINSYNC &&
|
|
peer->leap != LEAP_NOTINSYNC &&
|
|
peer->crypto & CRYPTO_FLAG_TAI &&
|
|
!(peer->crypto & CRYPTO_FLAG_LEAP))
|
|
exten = crypto_args(peer, CRYPTO_TAI,
|
|
NULL);
|
|
break;
|
|
|
|
/*
|
|
* In client mode the digest, certificate, agreement
|
|
* parameters and cookie are required. The leapsecond
|
|
* table is optional. If broadcast client mode, the
|
|
* autokey values are required as well. 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.
|
|
*
|
|
* If neither the server or client have the agreement
|
|
* parameters, the protocol transmits the cookie in the
|
|
* clear. If the server has the parameters, the client
|
|
* requests them and the protocol blinds it using the
|
|
* agreed key. It is a protocol error if the client has
|
|
* the parameters but the server does not.
|
|
*
|
|
* If the crypto bit is lit, don't send requests.
|
|
*/
|
|
case MODE_CLIENT:
|
|
if (peer->flash & TEST9)
|
|
break;
|
|
/*
|
|
* Parameter and certificate.
|
|
*/
|
|
if (!peer->crypto)
|
|
exten = crypto_args(peer, CRYPTO_ASSOC,
|
|
sys_hostname);
|
|
else if (!(peer->crypto & CRYPTO_FLAG_VALID))
|
|
exten = crypto_args(peer, CRYPTO_CERT,
|
|
peer->issuer);
|
|
|
|
/*
|
|
* Identity
|
|
*/
|
|
else if (!(peer->crypto & CRYPTO_FLAG_VRFY))
|
|
exten = crypto_args(peer,
|
|
crypto_ident(peer), NULL);
|
|
|
|
/*
|
|
* Autokey
|
|
*/
|
|
else if (!(peer->crypto & CRYPTO_FLAG_AGREE))
|
|
exten = crypto_args(peer, CRYPTO_COOK,
|
|
NULL);
|
|
else if (!(peer->crypto & CRYPTO_FLAG_AUTO) &&
|
|
(peer->cast_flags & MDF_BCLNT))
|
|
exten = crypto_args(peer, CRYPTO_AUTO,
|
|
NULL);
|
|
|
|
/*
|
|
* Postamble. We can sign the certificate here,
|
|
* since there is no chance of deadlock.
|
|
*/
|
|
else if (sys_leap != LEAP_NOTINSYNC &&
|
|
!(peer->crypto & CRYPTO_FLAG_SIGN))
|
|
exten = crypto_args(peer, CRYPTO_SIGN,
|
|
sys_hostname);
|
|
else if (sys_leap != LEAP_NOTINSYNC &&
|
|
peer->crypto & CRYPTO_FLAG_TAI &&
|
|
!(peer->crypto & CRYPTO_FLAG_LEAP))
|
|
exten = crypto_args(peer, CRYPTO_TAI,
|
|
NULL);
|
|
break;
|
|
}
|
|
|
|
/*
|
|
* Build the extension fields as directed. A response to
|
|
* a request is always sent, even if an error. If an
|
|
* error occurs when sending a request, the crypto
|
|
* machinery broke or was misconfigured. In that case
|
|
* light the crypto bit to suppress further requests.
|
|
*/
|
|
if (peer->cmmd != NULL) {
|
|
peer->cmmd->associd = htonl(peer->associd);
|
|
sendlen += crypto_xmit(&xpkt, &peer->srcadr,
|
|
sendlen, peer->cmmd, 0);
|
|
free(peer->cmmd);
|
|
peer->cmmd = NULL;
|
|
}
|
|
if (exten != NULL) {
|
|
int ltemp = 0;
|
|
|
|
if (exten->opcode != 0) {
|
|
ltemp = crypto_xmit(&xpkt,
|
|
&peer->srcadr, sendlen, exten, 0);
|
|
if (ltemp == 0) {
|
|
peer->flash |= TEST9; /* crypto error */
|
|
free(exten);
|
|
return;
|
|
}
|
|
}
|
|
sendlen += ltemp;
|
|
free(exten);
|
|
}
|
|
|
|
/*
|
|
* If extension fields are present, we must use a
|
|
* private cookie value of zero. Don't send if the
|
|
* crypto bit is set and no extension field is present,
|
|
* but in that case give back the key. Most intricate.
|
|
*/
|
|
if (sendlen > LEN_PKT_NOMAC) {
|
|
session_key(&peer->dstadr->sin, &peer->srcadr,
|
|
xkeyid, 0, 2);
|
|
} else if (peer->flash & TEST9) {
|
|
authtrust(xkeyid, 0);
|
|
return;
|
|
}
|
|
}
|
|
#endif /* OPENSSL */
|
|
|
|
/*
|
|
* Stash the transmit timestamp corrected for the encryption
|
|
* delay. If autokey, give back the key, as we use keys only
|
|
* once. Check for errors such as missing keys, buffer overflow,
|
|
* etc.
|
|
*/
|
|
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_INFO, "transmit: %s key %u not found",
|
|
stoa(&peer->srcadr), xkeyid);
|
|
peer->flash |= TEST9; /* no key found */
|
|
return;
|
|
}
|
|
sendlen += authlen;
|
|
#ifdef OPENSSL
|
|
if (xkeyid > NTP_MAXKEY)
|
|
authtrust(xkeyid, 0);
|
|
#endif /* OPENSSL */
|
|
get_systime(&xmt_tx);
|
|
if (sendlen > sizeof(xpkt)) {
|
|
msyslog(LOG_ERR, "buffer overflow %u", sendlen);
|
|
exit (-1);
|
|
}
|
|
sendpkt(&peer->srcadr, peer->dstadr, sys_ttl[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 OPENSSL
|
|
#ifdef DEBUG
|
|
if (debug)
|
|
printf(
|
|
"transmit: at %ld %s->%s mode %d keyid %08x len %d mac %d index %d\n",
|
|
current_time, peer->dstadr ? ntoa(&peer->dstadr->sin) : "-",
|
|
ntoa(&peer->srcadr), peer->hmode, xkeyid, sendlen -
|
|
authlen, 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, peer->dstadr ? ntoa(&peer->dstadr->sin) : "-",
|
|
ntoa(&peer->srcadr), peer->hmode, xkeyid, sendlen -
|
|
authlen, authlen);
|
|
#endif
|
|
#endif /* OPENSSL */
|
|
}
|
|
|
|
|
|
/*
|
|
* 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; /* timestamp */
|
|
l_fp xmt_tx; /* timestamp after authent */
|
|
int sendlen, authlen;
|
|
#ifdef OPENSSL
|
|
u_int32 temp32;
|
|
#endif
|
|
|
|
/*
|
|
* 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 gazoutta must
|
|
* go out another way.
|
|
*
|
|
* The root delay field is special. If the system stratum is
|
|
* less than the orphan stratum, send the real root delay.
|
|
* Otherwise, if there is no system peer, send the orphan delay.
|
|
* Otherwise, we must be an orphan parent, so send zero.
|
|
*/
|
|
rpkt = &rbufp->recv_pkt;
|
|
if (rbufp->dstadr->flags & INT_MCASTOPEN)
|
|
rbufp->dstadr = findinterface(&rbufp->recv_srcadr);
|
|
|
|
/*
|
|
* This is deliciously complicated. There are four cases.
|
|
*
|
|
* case leap stratum refid delay dispersion
|
|
*
|
|
* KoD 11 16 KISS system system
|
|
* normal system system system system system
|
|
* orphan child 00 orphan system orphan system
|
|
* orphan parent 00 orphan loopbk 0 0
|
|
*/
|
|
/*
|
|
* This is a kiss-of-death (KoD) packet. Show leap
|
|
* unsynchronized, stratum zero, reference ID the four-character
|
|
* kiss code and system root delay. Note the rate limit on these
|
|
* packets. Once a second initialize a bucket counter. Every
|
|
* packet sent decrements the counter until reaching zero. If
|
|
* the counter is zero, drop the kiss.
|
|
*/
|
|
if (mask & RES_LIMITED) {
|
|
sys_limitrejected++;
|
|
if (sys_kod == 0 || !(mask & RES_DEMOBILIZE))
|
|
return;
|
|
|
|
sys_kod--;
|
|
xpkt.li_vn_mode = PKT_LI_VN_MODE(LEAP_NOTINSYNC,
|
|
PKT_VERSION(rpkt->li_vn_mode), xmode);
|
|
xpkt.stratum = STRATUM_UNSPEC;
|
|
memcpy(&xpkt.refid, "RATE", 4);
|
|
xpkt.rootdelay = HTONS_FP(DTOFP(sys_rootdelay));
|
|
xpkt.rootdispersion =
|
|
HTONS_FP(DTOUFP(sys_rootdispersion));
|
|
|
|
/*
|
|
* This is a normal packet. Use the system variables.
|
|
*/
|
|
} else if (sys_stratum < sys_orphan) {
|
|
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.rootdelay = HTONS_FP(DTOFP(sys_rootdelay));
|
|
xpkt.rootdispersion =
|
|
HTONS_FP(DTOUFP(sys_rootdispersion));
|
|
|
|
/*
|
|
* This is a orphan child packet. The host is synchronized to an
|
|
* orphan parent. Show leap synchronized, orphan stratum, system
|
|
* reference ID and orphan root delay.
|
|
*/
|
|
} else if (sys_peer != NULL) {
|
|
xpkt.li_vn_mode = PKT_LI_VN_MODE(LEAP_NOWARNING,
|
|
PKT_VERSION(rpkt->li_vn_mode), xmode);
|
|
xpkt.stratum = STRATUM_TO_PKT(sys_orphan);
|
|
xpkt.refid = sys_refid;
|
|
xpkt.rootdelay = HTONS_FP(DTOFP(sys_orphandelay));
|
|
xpkt.rootdispersion =
|
|
HTONS_FP(DTOUFP(sys_rootdispersion));
|
|
|
|
/*
|
|
* This is an orphan parent. Show leap synchronized, orphan
|
|
* stratum, loopack reference ID and zero root delay.
|
|
*/
|
|
} else {
|
|
xpkt.li_vn_mode = PKT_LI_VN_MODE(LEAP_NOWARNING,
|
|
PKT_VERSION(rpkt->li_vn_mode), xmode);
|
|
xpkt.stratum = STRATUM_TO_PKT(sys_orphan);
|
|
xpkt.refid = htonl(LOOPBACKADR);
|
|
xpkt.rootdelay = HTONS_FP(DTOFP(0));
|
|
xpkt.rootdispersion = HTONS_FP(DTOFP(0));
|
|
}
|
|
xpkt.ppoll = rpkt->ppoll;
|
|
xpkt.precision = sys_precision;
|
|
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, stoa(&rbufp->dstadr->sin),
|
|
stoa(&rbufp->recv_srcadr), xmode);
|
|
#endif
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* The received packet contains a MAC, so the transmitted packet
|
|
* must be authenticated. For symmetric key cryptography, use
|
|
* the predefined and trusted symmetric 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 OPENSSL
|
|
if (xkeyid > NTP_MAXKEY) {
|
|
keyid_t cookie;
|
|
|
|
/*
|
|
* 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.
|
|
*/
|
|
cookie = session_key(&rbufp->recv_srcadr,
|
|
&rbufp->dstadr->sin, 0, sys_private, 0);
|
|
if (rbufp->recv_length >= (int)(sendlen + MAX_MAC_LEN +
|
|
2 * sizeof(u_int32))) {
|
|
session_key(&rbufp->dstadr->sin,
|
|
&rbufp->recv_srcadr, xkeyid, 0, 2);
|
|
temp32 = CRYPTO_RESP;
|
|
rpkt->exten[0] |= htonl(temp32);
|
|
sendlen += crypto_xmit(&xpkt,
|
|
&rbufp->recv_srcadr, sendlen,
|
|
(struct exten *)rpkt->exten, cookie);
|
|
} else {
|
|
session_key(&rbufp->dstadr->sin,
|
|
&rbufp->recv_srcadr, xkeyid, cookie, 2);
|
|
}
|
|
}
|
|
#endif /* OPENSSL */
|
|
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 OPENSSL
|
|
if (xkeyid > NTP_MAXKEY)
|
|
authtrust(xkeyid, 0);
|
|
#endif /* OPENSSL */
|
|
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, authlen);
|
|
#endif
|
|
}
|
|
|
|
|
|
#ifdef OPENSSL
|
|
/*
|
|
* 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;
|
|
}
|
|
value_free(&peer->sndval);
|
|
peer->keynumber = 0;
|
|
#ifdef DEBUG
|
|
if (debug)
|
|
printf("key_expire: at %lu\n", current_time);
|
|
#endif
|
|
}
|
|
#endif /* OPENSSL */
|
|
|
|
|
|
/*
|
|
* Determine if the peer is unfit for synchronization
|
|
*
|
|
* A peer is unfit for synchronization if
|
|
* > TEST10 bad leap or stratum below floor or at or above ceiling
|
|
* > TEST11 root distance exceeded
|
|
* > TEST12 a direct or indirect synchronization loop would form
|
|
* > TEST13 unreachable or noselect
|
|
*/
|
|
int /* FALSE if fit, TRUE if unfit */
|
|
peer_unfit(
|
|
struct peer *peer /* peer structure pointer */
|
|
)
|
|
{
|
|
int rval = 0;
|
|
|
|
/*
|
|
* A stratum error occurs if (1) the server has never been
|
|
* synchronized, (2) the server stratum is below the floor or
|
|
* greater than or equal to the ceiling, (3) the system stratum
|
|
* is below the orphan stratum and the server stratum is greater
|
|
* than or equal to the orphan stratum.
|
|
*/
|
|
if (peer->leap == LEAP_NOTINSYNC || peer->stratum < sys_floor ||
|
|
peer->stratum >= sys_ceiling || (sys_stratum < sys_orphan &&
|
|
peer->stratum >= sys_orphan))
|
|
rval |= TEST10; /* stratum out of bounds */
|
|
|
|
/*
|
|
* A distance error occurs if the root distance is greater than
|
|
* or equal to the distance threshold plus the increment due to
|
|
* one poll interval.
|
|
*/
|
|
if (root_distance(peer) >= sys_maxdist + clock_phi *
|
|
ULOGTOD(sys_poll))
|
|
rval |= TEST11; /* distance exceeded */
|
|
|
|
/*
|
|
* A loop error occurs if the remote peer is synchronized to the
|
|
* local peer of if the remote peer is synchronized to the same
|
|
* server as the local peer, but only if the remote peer is not
|
|
* the orphan parent.
|
|
*/
|
|
if (peer->stratum > 1 && peer->refid != htonl(LOOPBACKADR) &&
|
|
((!peer->dstadr || peer->refid == peer->dstadr->addr_refid) ||
|
|
peer->refid == sys_refid))
|
|
rval |= TEST12; /* synch loop */
|
|
|
|
/*
|
|
* An unreachable error occurs if the server is unreachable or
|
|
* the noselect bit is set.
|
|
*/
|
|
if (!peer->reach || peer->flags & FLAG_NOSELECT)
|
|
rval |= TEST13; /* unreachable */
|
|
|
|
peer->flash &= ~PEER_TEST_MASK;
|
|
peer->flash |= rval;
|
|
return (rval);
|
|
}
|
|
|
|
|
|
/*
|
|
* Find the precision of this particular machine
|
|
*/
|
|
#define MINSTEP 100e-9 /* minimum clock increment (s) */
|
|
#define MAXSTEP 20e-3 /* maximum clock increment (s) */
|
|
#define MINLOOPS 5 /* minimum number of step samples */
|
|
|
|
/*
|
|
* This routine calculates the system precision, defined as the minimum
|
|
* of a sequence of differences between successive readings of the
|
|
* system clock. However, if the system clock can be read more than once
|
|
* during a tick interval, the difference can be zero or one LSB unit,
|
|
* where the LSB corresponds to one nanosecond or one microsecond.
|
|
* Conceivably, if some other process preempts this one and reads the
|
|
* clock, the difference can be more than one LSB unit.
|
|
*
|
|
* For hardware clock frequencies of 10 MHz or less, we assume the
|
|
* logical clock advances only at the hardware clock tick. For higher
|
|
* frequencies, we assume the logical clock can advance no more than 100
|
|
* nanoseconds between ticks.
|
|
*/
|
|
int
|
|
default_get_precision(void)
|
|
{
|
|
l_fp val; /* current seconds fraction */
|
|
l_fp last; /* last seconds fraction */
|
|
l_fp diff; /* difference */
|
|
double tick; /* computed tick value */
|
|
double dtemp; /* scratch */
|
|
int i; /* log2 precision */
|
|
|
|
/*
|
|
* Loop to find tick value in nanoseconds. Toss out outlyer
|
|
* values less than the minimun tick value. In wacky cases, use
|
|
* the default maximum value.
|
|
*/
|
|
get_systime(&last);
|
|
tick = MAXSTEP;
|
|
for (i = 0; i < MINLOOPS;) {
|
|
get_systime(&val);
|
|
diff = val;
|
|
L_SUB(&diff, &last);
|
|
last = val;
|
|
LFPTOD(&diff, dtemp);
|
|
if (dtemp < MINSTEP)
|
|
continue;
|
|
i++;
|
|
if (dtemp < tick)
|
|
tick = dtemp;
|
|
}
|
|
|
|
/*
|
|
* Find the nearest power of two.
|
|
*/
|
|
NLOG(NLOG_SYSEVENT)
|
|
msyslog(LOG_INFO, "precision = %.3f usec", tick * 1e6);
|
|
for (i = 0; tick <= 1; i++)
|
|
tick *= 2;
|
|
if (tick - 1. > 1. - tick / 2)
|
|
i--;
|
|
return (-i);
|
|
}
|
|
|
|
|
|
/*
|
|
* kod_proto - called once per second to limit kiss-of-death packets
|
|
*/
|
|
void
|
|
kod_proto(void)
|
|
{
|
|
sys_kod = sys_kod_rate;
|
|
}
|
|
|
|
|
|
/*
|
|
* init_proto - initialize the protocol module's data
|
|
*/
|
|
void
|
|
init_proto(void)
|
|
{
|
|
l_fp dummy;
|
|
int i;
|
|
|
|
/*
|
|
* Fill in the sys_* stuff. Default is don't listen to
|
|
* broadcasting, authenticate.
|
|
*/
|
|
sys_leap = LEAP_NOTINSYNC;
|
|
sys_stratum = STRATUM_UNSPEC;
|
|
memcpy(&sys_refid, "INIT", 4);
|
|
sys_precision = (s_char)default_get_precision();
|
|
sys_jitter = LOGTOD(sys_precision);
|
|
sys_rootdelay = 0;
|
|
sys_orphandelay = (double)(ntp_random() & 0xffff) / 65536. *
|
|
sys_maxdist;
|
|
sys_rootdispersion = 0;
|
|
L_CLR(&sys_reftime);
|
|
sys_peer = NULL;
|
|
sys_survivors = 0;
|
|
get_systime(&dummy);
|
|
sys_manycastserver = 0;
|
|
sys_bclient = 0;
|
|
sys_bdelay = DEFBROADDELAY;
|
|
sys_calldelay = BURST_DELAY;
|
|
sys_authenticate = 1;
|
|
L_CLR(&sys_authdelay);
|
|
sys_authdly[0] = sys_authdly[1] = 0;
|
|
sys_stattime = 0;
|
|
proto_clr_stats();
|
|
for (i = 0; i < MAX_TTL; i++) {
|
|
sys_ttl[i] = (u_char)((i * 256) / MAX_TTL);
|
|
sys_ttlmax = i;
|
|
}
|
|
#ifdef OPENSSL
|
|
sys_automax = 1 << NTP_AUTOMAX;
|
|
#endif /* OPENSSL */
|
|
|
|
/*
|
|
* Default these to enable
|
|
*/
|
|
ntp_enable = 1;
|
|
#ifndef KERNEL_FLL_BUG
|
|
kern_enable = 1;
|
|
#endif
|
|
pps_enable = 0;
|
|
stats_control = 1;
|
|
}
|
|
|
|
|
|
/*
|
|
* proto_config - configure the protocol module
|
|
*/
|
|
void
|
|
proto_config(
|
|
int item,
|
|
u_long value,
|
|
double dvalue,
|
|
struct sockaddr_storage* svalue
|
|
)
|
|
{
|
|
/*
|
|
* Figure out what he wants to change, then do it
|
|
*/
|
|
switch (item) {
|
|
|
|
/*
|
|
* Turn on/off kernel discipline.
|
|
*/
|
|
case PROTO_KERNEL:
|
|
kern_enable = (int)value;
|
|
break;
|
|
|
|
/*
|
|
* Turn on/off clock discipline.
|
|
*/
|
|
case PROTO_NTP:
|
|
ntp_enable = (int)value;
|
|
break;
|
|
|
|
/*
|
|
* Turn on/off monitoring.
|
|
*/
|
|
case PROTO_MONITOR:
|
|
if (value)
|
|
mon_start(MON_ON);
|
|
else
|
|
mon_stop(MON_ON);
|
|
break;
|
|
|
|
/*
|
|
* Turn on/off statistics.
|
|
*/
|
|
case PROTO_FILEGEN:
|
|
stats_control = (int)value;
|
|
break;
|
|
|
|
/*
|
|
* Turn on/off enable broadcasts.
|
|
*/
|
|
case PROTO_BROADCLIENT:
|
|
sys_bclient = (int)value;
|
|
if (sys_bclient == 0)
|
|
io_unsetbclient();
|
|
else
|
|
io_setbclient();
|
|
break;
|
|
|
|
/*
|
|
* Turn on/off PPS discipline.
|
|
*/
|
|
case PROTO_PPS:
|
|
pps_enable = (int)value;
|
|
break;
|
|
|
|
/*
|
|
* Add muliticast group address.
|
|
*/
|
|
case PROTO_MULTICAST_ADD:
|
|
if (svalue)
|
|
io_multicast_add(*svalue);
|
|
sys_bclient = 1;
|
|
break;
|
|
|
|
/*
|
|
* Delete multicast group address.
|
|
*/
|
|
case PROTO_MULTICAST_DEL:
|
|
if (svalue)
|
|
io_multicast_del(*svalue);
|
|
break;
|
|
|
|
/*
|
|
* Set default broadcast delay.
|
|
*/
|
|
case PROTO_BROADDELAY:
|
|
sys_bdelay = dvalue;
|
|
break;
|
|
|
|
/*
|
|
* Set modem call delay.
|
|
*/
|
|
case PROTO_CALLDELAY:
|
|
sys_calldelay = (int)value;
|
|
break;
|
|
|
|
/*
|
|
* Turn on/off authentication to mobilize ephemeral
|
|
* associations.
|
|
*/
|
|
case PROTO_AUTHENTICATE:
|
|
sys_authenticate = (int)value;
|
|
break;
|
|
|
|
/*
|
|
* Set minimum number of survivors.
|
|
*/
|
|
case PROTO_MINCLOCK:
|
|
sys_minclock = (int)dvalue;
|
|
break;
|
|
|
|
/*
|
|
* Set maximum number of preemptable associations.
|
|
*/
|
|
case PROTO_MAXCLOCK:
|
|
sys_maxclock = (int)dvalue;
|
|
break;
|
|
|
|
/*
|
|
* Set minimum number of survivors.
|
|
*/
|
|
case PROTO_MINSANE:
|
|
sys_minsane = (int)dvalue;
|
|
break;
|
|
|
|
/*
|
|
* Set stratum floor.
|
|
*/
|
|
case PROTO_FLOOR:
|
|
sys_floor = (int)dvalue;
|
|
break;
|
|
|
|
/*
|
|
* Set stratum ceiling.
|
|
*/
|
|
case PROTO_CEILING:
|
|
sys_ceiling = (int)dvalue;
|
|
break;
|
|
|
|
/*
|
|
* Set orphan stratum.
|
|
*/
|
|
case PROTO_ORPHAN:
|
|
sys_orphan = (int)dvalue;
|
|
break;
|
|
|
|
/*
|
|
* Set cohort switch.
|
|
*/
|
|
case PROTO_COHORT:
|
|
sys_cohort = (int)dvalue;
|
|
break;
|
|
|
|
/*
|
|
* Set minimum dispersion increment.
|
|
*/
|
|
case PROTO_MINDISP:
|
|
sys_mindisp = dvalue;
|
|
break;
|
|
|
|
/*
|
|
* Set maximum distance (select threshold).
|
|
*/
|
|
case PROTO_MAXDIST:
|
|
sys_maxdist = dvalue;
|
|
break;
|
|
|
|
/*
|
|
* Set anticlockhop threshold.
|
|
*/
|
|
case PROTO_MAXHOP:
|
|
sys_maxhop = (int)dvalue;
|
|
break;
|
|
|
|
/*
|
|
* Set adjtime() resolution (s).
|
|
*/
|
|
case PROTO_ADJ:
|
|
sys_tick = dvalue;
|
|
break;
|
|
|
|
/*
|
|
* Set manycast beacon interval.
|
|
*/
|
|
case PROTO_BEACON:
|
|
sys_beacon = (int)dvalue;
|
|
break;
|
|
|
|
#ifdef REFCLOCK
|
|
/*
|
|
* Turn on/off refclock calibrate
|
|
*/
|
|
case PROTO_CAL:
|
|
cal_enable = (int)value;
|
|
break;
|
|
#endif /* REFCLOCK */
|
|
default:
|
|
|
|
/*
|
|
* Log this error.
|
|
*/
|
|
msyslog(LOG_INFO,
|
|
"proto_config: illegal item %d, value %ld", item,
|
|
value);
|
|
}
|
|
}
|
|
|
|
|
|
/*
|
|
* proto_clr_stats - clear protocol stat counters
|
|
*/
|
|
void
|
|
proto_clr_stats(void)
|
|
{
|
|
sys_stattime = current_time;
|
|
sys_received = 0;
|
|
sys_processed = 0;
|
|
sys_newversionpkt = 0;
|
|
sys_oldversionpkt = 0;
|
|
sys_unknownversion = 0;
|
|
sys_restricted = 0;
|
|
sys_badlength = 0;
|
|
sys_badauth = 0;
|
|
sys_limitrejected = 0;
|
|
}
|