2 * ntp_proto.c - NTP version 4 protocol machinery
4 * ATTENTION: Get approval from Dave Mills on all changes to this file!
12 #include "ntp_stdlib.h"
13 #include "ntp_unixtime.h"
14 #include "ntp_control.h"
15 #include "ntp_string.h"
16 #include "ntp_leapsec.h"
17 #include "refidsmear.h"
18 #include "lib_strbuf.h"
29 * This macro defines the authentication state. If x is 1 authentication
30 * is required; othewise it is optional.
32 #define AUTH(x, y) ((x) ? (y) == AUTH_OK \
33 : (y) == AUTH_OK || (y) == AUTH_NONE)
35 #define AUTH_NONE 0 /* authentication not required */
36 #define AUTH_OK 1 /* authentication OK */
37 #define AUTH_ERROR 2 /* authentication error */
38 #define AUTH_CRYPTO 3 /* crypto_NAK */
41 * Set up Kiss Code values
45 NOKISS, /* No Kiss Code */
46 RATEKISS, /* Rate limit Kiss Code */
47 DENYKISS, /* Deny Kiss */
48 RSTRKISS, /* Restricted Kiss */
49 XKISS, /* Experimental Kiss */
50 UNKNOWNKISS /* Unknown Kiss Code */
54 * traffic shaping parameters
56 #define NTP_IBURST 6 /* packets in iburst */
57 #define RESP_DELAY 1 /* refclock burst delay (s) */
60 * pool soliciting restriction duration (s)
62 #define POOL_SOLICIT_WINDOW 8
65 * peer_select groups statistics for a peer used by clock_select() and
68 typedef struct peer_select_tag {
70 double synch; /* sync distance */
71 double error; /* jitter */
72 double seljit; /* selection jitter */
76 * System variables are declared here. Unless specified otherwise, all
77 * times are in seconds.
79 u_char sys_leap; /* system leap indicator, use set_sys_leap() to change this */
80 u_char xmt_leap; /* leap indicator sent in client requests, set up by set_sys_leap() */
81 u_char sys_stratum; /* system stratum */
82 s_char sys_precision; /* local clock precision (log2 s) */
83 double sys_rootdelay; /* roundtrip delay to primary source */
84 double sys_rootdisp; /* dispersion to primary source */
85 u_int32 sys_refid; /* reference id (network byte order) */
86 l_fp sys_reftime; /* last update time */
87 struct peer *sys_peer; /* current peer */
90 struct leap_smear_info leap_smear;
92 int leap_sec_in_progress;
95 * Rate controls. Leaky buckets are used to throttle the packet
96 * transmission rates in order to protect busy servers such as at NIST
97 * and USNO. There is a counter for each association and another for KoD
98 * packets. The association counter decrements each second, but not
99 * below zero. Each time a packet is sent the counter is incremented by
100 * a configurable value representing the average interval between
101 * packets. A packet is delayed as long as the counter is greater than
102 * zero. Note this does not affect the time value computations.
105 * Nonspecified system state variables
107 int sys_bclient; /* broadcast client enable */
108 double sys_bdelay; /* broadcast client default delay */
109 int sys_authenticate; /* requre authentication for config */
110 l_fp sys_authdelay; /* authentication delay */
111 double sys_offset; /* current local clock offset */
112 double sys_mindisp = MINDISPERSE; /* minimum distance (s) */
113 double sys_maxdist = MAXDISTANCE; /* selection threshold */
114 double sys_jitter; /* system jitter */
115 u_long sys_epoch; /* last clock update time */
116 static double sys_clockhop; /* clockhop threshold */
117 static int leap_vote_ins; /* leap consensus for insert */
118 static int leap_vote_del; /* leap consensus for delete */
119 keyid_t sys_private; /* private value for session seed */
120 int sys_manycastserver; /* respond to manycast client pkts */
121 int ntp_mode7; /* respond to ntpdc (mode7) */
122 int peer_ntpdate; /* active peers in ntpdate mode */
123 int sys_survivors; /* truest of the truechimers */
124 char *sys_ident = NULL; /* identity scheme */
127 * TOS and multicast mapping stuff
129 int sys_floor = 0; /* cluster stratum floor */
130 int sys_ceiling = STRATUM_UNSPEC - 1; /* cluster stratum ceiling */
131 int sys_minsane = 1; /* minimum candidates */
132 int sys_minclock = NTP_MINCLOCK; /* minimum candidates */
133 int sys_maxclock = NTP_MAXCLOCK; /* maximum candidates */
134 int sys_cohort = 0; /* cohort switch */
135 int sys_orphan = STRATUM_UNSPEC + 1; /* orphan stratum */
136 int sys_orphwait = NTP_ORPHWAIT; /* orphan wait */
137 int sys_beacon = BEACON; /* manycast beacon interval */
138 int sys_ttlmax; /* max ttl mapping vector index */
139 u_char sys_ttl[MAX_TTL]; /* ttl mapping vector */
142 * Statistics counters - first the good, then the bad
144 u_long sys_stattime; /* elapsed time */
145 u_long sys_received; /* packets received */
146 u_long sys_processed; /* packets for this host */
147 u_long sys_newversion; /* current version */
148 u_long sys_oldversion; /* old version */
149 u_long sys_restricted; /* access denied */
150 u_long sys_badlength; /* bad length or format */
151 u_long sys_badauth; /* bad authentication */
152 u_long sys_declined; /* declined */
153 u_long sys_limitrejected; /* rate exceeded */
154 u_long sys_kodsent; /* KoD sent */
156 static int kiss_code_check(u_char hisleap, u_char hisstratum, u_char hismode, u_int32 refid);
157 static double root_distance (struct peer *);
158 static void clock_combine (peer_select *, int, int);
159 static void peer_xmit (struct peer *);
160 static void fast_xmit (struct recvbuf *, int, keyid_t, int);
161 static void pool_xmit (struct peer *);
162 static void clock_update (struct peer *);
163 static void measure_precision(void);
164 static double measure_tick_fuzz(void);
165 static int local_refid (struct peer *);
166 static int peer_unfit (struct peer *);
168 static int group_test (char *, char *);
171 void pool_name_resolved (int, int, void *, const char *,
172 const char *, const struct addrinfo *,
173 const struct addrinfo *);
176 const char * amtoa (int am);
184 sys_leap = new_sys_leap;
188 * Under certain conditions we send faked leap bits to clients, so
189 * eventually change xmt_leap below, but never change LEAP_NOTINSYNC.
191 if (xmt_leap != LEAP_NOTINSYNC) {
192 if (leap_sec_in_progress) {
193 /* always send "not sync" */
194 xmt_leap = LEAP_NOTINSYNC;
199 * If leap smear is enabled in general we must
200 * never send a leap second warning to clients,
201 * so make sure we only send "in sync".
203 if (leap_smear.enabled)
204 xmt_leap = LEAP_NOWARNING;
206 #endif /* LEAP_SMEAR */
223 if ( hismode == MODE_SERVER
224 && hisleap == LEAP_NOTINSYNC
225 && hisstratum == STRATUM_UNSPEC) {
226 if(memcmp(&refid,"RATE", 4) == 0) {
228 } else if(memcmp(&refid,"DENY", 4) == 0) {
230 } else if(memcmp(&refid,"RSTR", 4) == 0) {
232 } else if(memcmp(&refid,"X", 1) == 0) {
235 return (UNKNOWNKISS);
244 * transmit - transmit procedure called by poll timeout
248 struct peer *peer /* peer structure pointer */
254 * The polling state machine. There are two kinds of machines,
255 * those that never expect a reply (broadcast and manycast
256 * server modes) and those that do (all other modes). The dance
262 * In broadcast mode the poll interval is never changed from
265 if (peer->cast_flags & (MDF_BCAST | MDF_MCAST)) {
266 peer->outdate = current_time;
267 if (sys_leap != LEAP_NOTINSYNC)
269 poll_update(peer, hpoll);
274 * In manycast mode we start with unity ttl. The ttl is
275 * increased by one for each poll until either sys_maxclock
276 * servers have been found or the maximum ttl is reached. When
277 * sys_maxclock servers are found we stop polling until one or
278 * more servers have timed out or until less than sys_minclock
279 * associations turn up. In this case additional better servers
280 * are dragged in and preempt the existing ones. Once every
281 * sys_beacon seconds we are to transmit unconditionally, but
282 * this code is not quite right -- peer->unreach counts polls
283 * and is being compared with sys_beacon, so the beacons happen
284 * every sys_beacon polls.
286 if (peer->cast_flags & MDF_ACAST) {
287 peer->outdate = current_time;
288 if (peer->unreach > sys_beacon) {
292 } else if ( sys_survivors < sys_minclock
293 || peer_associations < sys_maxclock) {
294 if (peer->ttl < (u_int32)sys_ttlmax)
299 poll_update(peer, hpoll);
304 * Pool associations transmit unicast solicitations when there
305 * are less than a hard limit of 2 * sys_maxclock associations,
306 * and either less than sys_minclock survivors or less than
307 * sys_maxclock associations. The hard limit prevents unbounded
308 * growth in associations if the system clock or network quality
309 * result in survivor count dipping below sys_minclock often.
310 * This was observed testing with pool, where sys_maxclock == 12
311 * resulted in 60 associations without the hard limit. A
312 * similar hard limit on manycastclient ephemeral associations
313 * may be appropriate.
315 if (peer->cast_flags & MDF_POOL) {
316 peer->outdate = current_time;
317 if ( (peer_associations <= 2 * sys_maxclock)
318 && ( peer_associations < sys_maxclock
319 || sys_survivors < sys_minclock))
321 poll_update(peer, hpoll);
326 * In unicast modes the dance is much more intricate. It is
327 * designed to back off whenever possible to minimize network
330 if (peer->burst == 0) {
334 * Update the reachability status. If not heard for
335 * three consecutive polls, stuff infinity in the clock
338 oreach = peer->reach;
339 peer->outdate = current_time;
345 * Here the peer is unreachable. If it was
346 * previously reachable raise a trap. Send a
349 clock_filter(peer, 0., 0., MAXDISPERSE);
352 report_event(PEVNT_UNREACH, peer, NULL);
354 if ( (peer->flags & FLAG_IBURST)
356 peer->retry = NTP_RETRY;
360 * Here the peer is reachable. Send a burst if
361 * enabled and the peer is fit. Reset unreach
362 * for persistent and ephemeral associations.
363 * Unreach is also reset for survivors in
367 if (!(peer->flags & FLAG_PREEMPT))
369 if ( (peer->flags & FLAG_BURST)
371 && !peer_unfit(peer))
372 peer->retry = NTP_RETRY;
376 * Watch for timeout. If ephemeral, toss the rascal;
377 * otherwise, bump the poll interval. Note the
378 * poll_update() routine will clamp it to maxpoll.
379 * If preemptible and we have more peers than maxclock,
380 * and this peer has the minimum score of preemptibles,
383 if (peer->unreach >= NTP_UNREACH) {
385 /* ephemeral: no FLAG_CONFIG nor FLAG_PREEMPT */
386 if (!(peer->flags & (FLAG_CONFIG | FLAG_PREEMPT))) {
387 report_event(PEVNT_RESTART, peer, "timeout");
388 peer_clear(peer, "TIME");
392 if ( (peer->flags & FLAG_PREEMPT)
393 && (peer_associations > sys_maxclock)
394 && score_all(peer)) {
395 report_event(PEVNT_RESTART, peer, "timeout");
396 peer_clear(peer, "TIME");
403 if (peer->burst == 0) {
406 * If ntpdate mode and the clock has not been
407 * set and all peers have completed the burst,
408 * we declare a successful failure.
412 if (peer_ntpdate == 0) {
414 "ntpd: no servers found");
417 "ntpd: no servers found\n");
427 * Do not transmit if in broadcast client mode.
429 if (peer->hmode != MODE_BCLIENT)
431 poll_update(peer, hpoll);
445 case AM_ERR: return "AM_ERR";
446 case AM_NOMATCH: return "AM_NOMATCH";
447 case AM_PROCPKT: return "AM_PROCPKT";
448 case AM_BCST: return "AM_BCST";
449 case AM_FXMIT: return "AM_FXMIT";
450 case AM_MANYCAST: return "AM_MANYCAST";
451 case AM_NEWPASS: return "AM_NEWPASS";
452 case AM_NEWBCL: return "AM_NEWBCL";
453 case AM_POSSBCL: return "AM_POSSBCL";
456 snprintf(bp, LIB_BUFLENGTH, "AM_#%d", am);
463 * receive - receive procedure called for each packet received
467 struct recvbuf *rbufp
470 register struct peer *peer; /* peer structure pointer */
471 register struct pkt *pkt; /* receive packet pointer */
472 u_char hisversion; /* packet version */
473 u_char hisleap; /* packet leap indicator */
474 u_char hismode; /* packet mode */
475 u_char hisstratum; /* packet stratum */
476 u_short restrict_mask; /* restrict bits */
477 const char *hm_str; /* hismode string */
478 const char *am_str; /* association match string */
479 int kissCode = NOKISS; /* Kiss Code */
480 int has_mac; /* length of MAC field */
481 int authlen; /* offset of MAC field */
482 int is_authentic = 0; /* cryptosum ok */
483 int retcode = AM_NOMATCH; /* match code */
484 keyid_t skeyid = 0; /* key IDs */
485 u_int32 opcode = 0; /* extension field opcode */
486 sockaddr_u *dstadr_sin; /* active runway */
487 struct peer *peer2; /* aux peer structure pointer */
488 endpt *match_ep; /* newpeer() local address */
489 l_fp p_org; /* origin timestamp */
490 l_fp p_rec; /* receive timestamp */
491 l_fp p_xmt; /* transmit timestamp */
493 char hostname[NTP_MAXSTRLEN + 1];
494 char *groupname = NULL;
495 struct autokey *ap; /* autokey structure pointer */
496 int rval; /* cookie snatcher */
497 keyid_t pkeyid = 0, tkeyid = 0; /* key IDs */
499 #ifdef HAVE_NTP_SIGND
500 static unsigned char zero_key[16];
501 #endif /* HAVE_NTP_SIGND */
504 * Monitor the packet and get restrictions. Note that the packet
505 * length for control and private mode packets must be checked
506 * by the service routines. Some restrictions have to be handled
507 * later in order to generate a kiss-o'-death packet.
510 * Bogus port check is before anything, since it probably
511 * reveals a clogging attack.
514 if (0 == SRCPORT(&rbufp->recv_srcadr)) {
516 return; /* bogus port */
518 restrict_mask = restrictions(&rbufp->recv_srcadr);
519 pkt = &rbufp->recv_pkt;
520 DPRINTF(2, ("receive: at %ld %s<-%s flags %x restrict %03x org %#010x.%08x xmt %#010x.%08x\n",
521 current_time, stoa(&rbufp->dstadr->sin),
522 stoa(&rbufp->recv_srcadr), rbufp->dstadr->flags,
523 restrict_mask, ntohl(pkt->org.l_ui), ntohl(pkt->org.l_uf),
524 ntohl(pkt->xmt.l_ui), ntohl(pkt->xmt.l_uf)));
525 hisversion = PKT_VERSION(pkt->li_vn_mode);
526 hisleap = PKT_LEAP(pkt->li_vn_mode);
527 hismode = (int)PKT_MODE(pkt->li_vn_mode);
528 hisstratum = PKT_TO_STRATUM(pkt->stratum);
529 if (restrict_mask & RES_IGNORE) {
531 return; /* ignore everything */
533 if (hismode == MODE_PRIVATE) {
534 if (!ntp_mode7 || (restrict_mask & RES_NOQUERY)) {
536 return; /* no query private */
538 process_private(rbufp, ((restrict_mask &
539 RES_NOMODIFY) == 0));
542 if (hismode == MODE_CONTROL) {
543 if (restrict_mask & RES_NOQUERY) {
545 return; /* no query control */
547 process_control(rbufp, restrict_mask);
550 if (restrict_mask & RES_DONTSERVE) {
552 return; /* no time serve */
556 * This is for testing. If restricted drop ten percent of
559 if (restrict_mask & RES_FLAKE) {
560 if ((double)ntp_random() / 0x7fffffff < .1) {
562 return; /* no flakeway */
567 * Version check must be after the query packets, since they
568 * intentionally use an early version.
570 if (hisversion == NTP_VERSION) {
571 sys_newversion++; /* new version */
572 } else if ( !(restrict_mask & RES_VERSION)
573 && hisversion >= NTP_OLDVERSION) {
574 sys_oldversion++; /* previous version */
577 return; /* old version */
581 * Figure out his mode and validate the packet. This has some
582 * legacy raunch that probably should be removed. In very early
583 * NTP versions mode 0 was equivalent to what later versions
584 * would interpret as client mode.
586 if (hismode == MODE_UNSPEC) {
587 if (hisversion == NTP_OLDVERSION) {
588 hismode = MODE_CLIENT;
591 return; /* invalid mode */
596 * Parse the extension field if present. We figure out whether
597 * an extension field is present by measuring the MAC size. If
598 * the number of words following the packet header is 0, no MAC
599 * is present and the packet is not authenticated. If 1, the
600 * packet is a crypto-NAK; if 3, the packet is authenticated
601 * with DES; if 5, the packet is authenticated with MD5; if 6,
602 * the packet is authenticated with SHA. If 2 or * 4, the packet
603 * is a runt and discarded forthwith. If greater than 6, an
604 * extension field is present, so we subtract the length of the
605 * field and go around again.
607 authlen = LEN_PKT_NOMAC;
608 has_mac = rbufp->recv_length - authlen;
609 while (has_mac > 0) {
616 if (has_mac % 4 != 0 || has_mac < (int)MIN_MAC_LEN) {
618 return; /* bad length */
620 if (has_mac <= (int)MAX_MAC_LEN) {
621 skeyid = ntohl(((u_int32 *)pkt)[authlen / 4]);
625 opcode = ntohl(((u_int32 *)pkt)[authlen / 4]);
626 len = opcode & 0xffff;
629 || (int)len + authlen > rbufp->recv_length) {
631 return; /* bad length */
635 * Extract calling group name for later. If
636 * sys_groupname is non-NULL, there must be
637 * a group name provided to elicit a response.
639 if ( (opcode & 0x3fff0000) == CRYPTO_ASSOC
640 && sys_groupname != NULL) {
641 ep = (struct exten *)&((u_int32 *)pkt)[authlen / 4];
642 hostlen = ntohl(ep->vallen);
643 if ( hostlen >= sizeof(hostname)
645 offsetof(struct exten, pkt)) {
647 return; /* bad length */
649 memcpy(hostname, &ep->pkt, hostlen);
650 hostname[hostlen] = '\0';
651 groupname = strchr(hostname, '@');
652 if (groupname == NULL) {
665 * If has_mac is < 0 we had a malformed packet.
669 return; /* bad length */
673 * If authentication required, a MAC must be present.
675 if (restrict_mask & RES_DONTTRUST && has_mac == 0) {
677 return; /* access denied */
681 * Update the MRU list and finger the cloggers. It can be a
682 * little expensive, so turn it off for production use.
683 * RES_LIMITED and RES_KOD will be cleared in the returned
684 * restrict_mask unless one or both actions are warranted.
686 restrict_mask = ntp_monitor(rbufp, restrict_mask);
687 if (restrict_mask & RES_LIMITED) {
689 if ( !(restrict_mask & RES_KOD)
690 || MODE_BROADCAST == hismode
691 || MODE_SERVER == hismode) {
692 if (MODE_SERVER == hismode)
693 DPRINTF(1, ("Possibly self-induced rate limiting of MODE_SERVER from %s\n",
694 stoa(&rbufp->recv_srcadr)));
695 return; /* rate exceeded */
697 if (hismode == MODE_CLIENT)
698 fast_xmit(rbufp, MODE_SERVER, skeyid,
701 fast_xmit(rbufp, MODE_ACTIVE, skeyid,
703 return; /* rate exceeded */
705 restrict_mask &= ~RES_KOD;
708 * We have tossed out as many buggy packets as possible early in
709 * the game to reduce the exposure to a clogging attack. Now we
710 * have to burn some cycles to find the association and
711 * authenticate the packet if required. Note that we burn only
712 * digest cycles, again to reduce exposure. There may be no
713 * matching association and that's okay.
715 * More on the autokey mambo. Normally the local interface is
716 * found when the association was mobilized with respect to a
717 * designated remote address. We assume packets arriving from
718 * the remote address arrive via this interface and the local
719 * address used to construct the autokey is the unicast address
720 * of the interface. However, if the sender is a broadcaster,
721 * the interface broadcast address is used instead.
722 * Notwithstanding this technobabble, if the sender is a
723 * multicaster, the broadcast address is null, so we use the
724 * unicast address anyway. Don't ask.
726 peer = findpeer(rbufp, hismode, &retcode);
727 dstadr_sin = &rbufp->dstadr->sin;
728 NTOHL_FP(&pkt->org, &p_org);
729 NTOHL_FP(&pkt->rec, &p_rec);
730 NTOHL_FP(&pkt->xmt, &p_xmt);
731 hm_str = modetoa(hismode);
732 am_str = amtoa(retcode);
735 * Authentication is conditioned by three switches:
737 * NOPEER (RES_NOPEER) do not mobilize an association unless
739 * NOTRUST (RES_DONTTRUST) do not allow access unless
740 * authenticated (implies NOPEER)
741 * enable (sys_authenticate) master NOPEER switch, by default
744 * The NOPEER and NOTRUST can be specified on a per-client basis
745 * using the restrict command. The enable switch if on implies
746 * NOPEER for all clients. There are four outcomes:
748 * NONE The packet has no MAC.
749 * OK the packet has a MAC and authentication succeeds
750 * ERROR the packet has a MAC and authentication fails
751 * CRYPTO crypto-NAK. The MAC has four octets only.
753 * Note: The AUTH(x, y) macro is used to filter outcomes. If x
754 * is zero, acceptable outcomes of y are NONE and OK. If x is
755 * one, the only acceptable outcome of y is OK.
759 restrict_mask &= ~RES_MSSNTP;
760 is_authentic = AUTH_NONE; /* not required */
761 DPRINTF(2, ("receive: at %ld %s<-%s mode %d/%s:%s len %d org %#010x.%08x xmt %#010x.%08x NOMAC\n",
762 current_time, stoa(dstadr_sin),
763 stoa(&rbufp->recv_srcadr), hismode, hm_str, am_str,
765 ntohl(pkt->org.l_ui), ntohl(pkt->org.l_uf),
766 ntohl(pkt->xmt.l_ui), ntohl(pkt->xmt.l_uf)));
767 } else if (has_mac == 4) {
768 restrict_mask &= ~RES_MSSNTP;
769 is_authentic = AUTH_CRYPTO; /* crypto-NAK */
770 DPRINTF(2, ("receive: at %ld %s<-%s mode %d/%s:%s keyid %08x len %d auth %d org %#010x.%08x xmt %#010x.%08x MAC4\n",
771 current_time, stoa(dstadr_sin),
772 stoa(&rbufp->recv_srcadr), hismode, hm_str, am_str,
773 skeyid, authlen + has_mac, is_authentic,
774 ntohl(pkt->org.l_ui), ntohl(pkt->org.l_uf),
775 ntohl(pkt->xmt.l_ui), ntohl(pkt->xmt.l_uf)));
777 #ifdef HAVE_NTP_SIGND
779 * If the signature is 20 bytes long, the last 16 of
780 * which are zero, then this is a Microsoft client
781 * wanting AD-style authentication of the server's
784 * This is described in Microsoft's WSPP docs, in MS-SNTP:
785 * http://msdn.microsoft.com/en-us/library/cc212930.aspx
787 } else if ( has_mac == MAX_MD5_LEN
788 && (restrict_mask & RES_MSSNTP)
789 && (retcode == AM_FXMIT || retcode == AM_NEWPASS)
790 && (memcmp(zero_key, (char *)pkt + authlen + 4,
791 MAX_MD5_LEN - 4) == 0)) {
792 is_authentic = AUTH_NONE;
793 #endif /* HAVE_NTP_SIGND */
796 restrict_mask &= ~RES_MSSNTP;
799 * For autokey modes, generate the session key
800 * and install in the key cache. Use the socket
801 * broadcast or unicast address as appropriate.
803 if (crypto_flags && skeyid > NTP_MAXKEY) {
806 * More on the autokey dance (AKD). A cookie is
807 * constructed from public and private values.
808 * For broadcast packets, the cookie is public
809 * (zero). For packets that match no
810 * association, the cookie is hashed from the
811 * addresses and private value. For server
812 * packets, the cookie was previously obtained
813 * from the server. For symmetric modes, the
814 * cookie was previously constructed using an
815 * agreement protocol; however, should PKI be
816 * unavailable, we construct a fake agreement as
817 * the EXOR of the peer and host cookies.
819 * hismode ephemeral persistent
820 * =======================================
823 * client sys cookie 0%
824 * server 0% sys cookie
830 if (has_mac < (int)MAX_MD5_LEN) {
834 if (hismode == MODE_BROADCAST) {
837 * For broadcaster, use the interface
838 * broadcast address when available;
839 * otherwise, use the unicast address
840 * found when the association was
841 * mobilized. However, if this is from
842 * the wildcard interface, game over.
846 ANY_INTERFACE_CHOOSE(&rbufp->recv_srcadr)) {
848 return; /* no wildcard */
851 if (!SOCK_UNSPEC(&rbufp->dstadr->bcast))
853 &rbufp->dstadr->bcast;
854 } else if (peer == NULL) {
855 pkeyid = session_key(
856 &rbufp->recv_srcadr, dstadr_sin, 0,
859 pkeyid = peer->pcookie;
863 * The session key includes both the public
864 * values and cookie. In case of an extension
865 * field, the cookie used for authentication
866 * purposes is zero. Note the hash is saved for
867 * use later in the autokey mambo.
869 if (authlen > (int)LEN_PKT_NOMAC && pkeyid != 0) {
870 session_key(&rbufp->recv_srcadr,
871 dstadr_sin, skeyid, 0, 2);
872 tkeyid = session_key(
873 &rbufp->recv_srcadr, dstadr_sin,
876 tkeyid = session_key(
877 &rbufp->recv_srcadr, dstadr_sin,
885 * Compute the cryptosum. Note a clogging attack may
886 * succeed in bloating the key cache. If an autokey,
887 * purge it immediately, since we won't be needing it
888 * again. If the packet is authentic, it can mobilize an
889 * association. Note that there is no key zero.
891 if (!authdecrypt(skeyid, (u_int32 *)pkt, authlen,
893 is_authentic = AUTH_ERROR;
895 is_authentic = AUTH_OK;
897 if (crypto_flags && skeyid > NTP_MAXKEY)
898 authtrust(skeyid, 0);
900 DPRINTF(2, ("receive: at %ld %s<-%s mode %d/%s:%s keyid %08x len %d auth %d org %#010x.%08x xmt %#010x.%08x\n",
901 current_time, stoa(dstadr_sin),
902 stoa(&rbufp->recv_srcadr), hismode, hm_str, am_str,
903 skeyid, authlen + has_mac, is_authentic,
904 ntohl(pkt->org.l_ui), ntohl(pkt->org.l_uf),
905 ntohl(pkt->xmt.l_ui), ntohl(pkt->xmt.l_uf)));
909 * The association matching rules are implemented by a set of
910 * routines and an association table. A packet matching an
911 * association is processed by the peer process for that
912 * association. If there are no errors, an ephemeral association
913 * is mobilized: a broadcast packet mobilizes a broadcast client
914 * aassociation; a manycast server packet mobilizes a manycast
915 * client association; a symmetric active packet mobilizes a
916 * symmetric passive association.
921 * This is a client mode packet not matching any association. If
922 * an ordinary client, simply toss a server mode packet back
923 * over the fence. If a manycast client, we have to work a
929 * If authentication OK, send a server reply; otherwise,
932 if (!(rbufp->dstadr->flags & INT_MCASTOPEN)) {
933 if (AUTH(restrict_mask & RES_DONTTRUST,
935 fast_xmit(rbufp, MODE_SERVER, skeyid,
937 } else if (is_authentic == AUTH_ERROR) {
938 fast_xmit(rbufp, MODE_SERVER, 0,
948 * This must be manycast. Do not respond if not
949 * configured as a manycast server.
951 if (!sys_manycastserver) {
953 return; /* not enabled */
958 * Do not respond if not the same group.
960 if (group_test(groupname, NULL)) {
967 * Do not respond if we are not synchronized or our
968 * stratum is greater than the manycaster or the
969 * manycaster has already synchronized to us.
971 if ( sys_leap == LEAP_NOTINSYNC
972 || sys_stratum >= hisstratum
973 || (!sys_cohort && sys_stratum == hisstratum + 1)
974 || rbufp->dstadr->addr_refid == pkt->refid) {
976 return; /* no help */
980 * Respond only if authentication succeeds. Don't do a
981 * crypto-NAK, as that would not be useful.
983 if (AUTH(restrict_mask & RES_DONTTRUST, is_authentic))
984 fast_xmit(rbufp, MODE_SERVER, skeyid,
989 * This is a server mode packet returned in response to a client
990 * mode packet sent to a multicast group address (for
991 * manycastclient) or to a unicast address (for pool). The
992 * origin timestamp is a good nonce to reliably associate the
993 * reply with what was sent. If there is no match, that's
994 * curious and could be an intruder attempting to clog, so we
997 * If the packet is authentic and the manycastclient or pool
998 * association is found, we mobilize a client association and
999 * copy pertinent variables from the manycastclient or pool
1000 * association to the new client association. If not, just
1001 * ignore the packet.
1003 * There is an implosion hazard at the manycast client, since
1004 * the manycast servers send the server packet immediately. If
1005 * the guy is already here, don't fire up a duplicate.
1011 * Do not respond if not the same group.
1013 if (group_test(groupname, NULL)) {
1017 #endif /* AUTOKEY */
1018 if ((peer2 = findmanycastpeer(rbufp)) == NULL) {
1020 return; /* not enabled */
1022 if (!AUTH( (!(peer2->cast_flags & MDF_POOL)
1023 && sys_authenticate)
1024 || (restrict_mask & (RES_NOPEER |
1025 RES_DONTTRUST)), is_authentic)) {
1027 return; /* access denied */
1031 * Do not respond if unsynchronized or stratum is below
1032 * the floor or at or above the ceiling.
1034 if ( hisleap == LEAP_NOTINSYNC
1035 || hisstratum < sys_floor
1036 || hisstratum >= sys_ceiling) {
1038 return; /* no help */
1040 peer = newpeer(&rbufp->recv_srcadr, NULL, rbufp->dstadr,
1041 MODE_CLIENT, hisversion, peer2->minpoll,
1042 peer2->maxpoll, FLAG_PREEMPT |
1043 (FLAG_IBURST & peer2->flags), MDF_UCAST |
1044 MDF_UCLNT, 0, skeyid, sys_ident);
1047 return; /* ignore duplicate */
1051 * After each ephemeral pool association is spun,
1052 * accelerate the next poll for the pool solicitor so
1053 * the pool will fill promptly.
1055 if (peer2->cast_flags & MDF_POOL)
1056 peer2->nextdate = current_time + 1;
1059 * Further processing of the solicitation response would
1060 * simply detect its origin timestamp as bogus for the
1061 * brand-new association (it matches the prototype
1062 * association) and tinker with peer->nextdate delaying
1065 return; /* solicitation response handled */
1068 * This is the first packet received from a broadcast server. If
1069 * the packet is authentic and we are enabled as broadcast
1070 * client, mobilize a broadcast client association. We don't
1071 * kiss any frogs here.
1077 * Do not respond if not the same group.
1079 if (group_test(groupname, sys_ident)) {
1083 #endif /* AUTOKEY */
1084 if (sys_bclient == 0) {
1086 return; /* not enabled */
1088 if (!AUTH(sys_authenticate | (restrict_mask &
1089 (RES_NOPEER | RES_DONTTRUST)), is_authentic)) {
1091 return; /* access denied */
1095 * Do not respond if unsynchronized or stratum is below
1096 * the floor or at or above the ceiling.
1098 if ( hisleap == LEAP_NOTINSYNC
1099 || hisstratum < sys_floor
1100 || hisstratum >= sys_ceiling) {
1102 return; /* no help */
1107 * Do not respond if Autokey and the opcode is not a
1108 * CRYPTO_ASSOC response with association ID.
1110 if ( crypto_flags && skeyid > NTP_MAXKEY
1111 && (opcode & 0xffff0000) != (CRYPTO_ASSOC | CRYPTO_RESP)) {
1113 return; /* protocol error */
1115 #endif /* AUTOKEY */
1118 * Broadcasts received via a multicast address may
1119 * arrive after a unicast volley has begun
1120 * with the same remote address. newpeer() will not
1121 * find duplicate associations on other local endpoints
1122 * if a non-NULL endpoint is supplied. multicastclient
1123 * ephemeral associations are unique across all local
1126 if (!(INT_MCASTOPEN & rbufp->dstadr->flags))
1127 match_ep = rbufp->dstadr;
1132 * Determine whether to execute the initial volley.
1134 if (sys_bdelay != 0) {
1137 * If a two-way exchange is not possible,
1138 * neither is Autokey.
1140 if (crypto_flags && skeyid > NTP_MAXKEY) {
1142 return; /* no autokey */
1144 #endif /* AUTOKEY */
1147 * Do not execute the volley. Start out in
1148 * broadcast client mode.
1150 peer = newpeer(&rbufp->recv_srcadr, NULL,
1151 match_ep, MODE_BCLIENT, hisversion,
1152 pkt->ppoll, pkt->ppoll, FLAG_PREEMPT,
1153 MDF_BCLNT, 0, skeyid, sys_ident);
1156 return; /* ignore duplicate */
1159 peer->delay = sys_bdelay;
1165 * Execute the initial volley in order to calibrate the
1166 * propagation delay and run the Autokey protocol.
1168 * Note that the minpoll is taken from the broadcast
1169 * packet, normally 6 (64 s) and that the poll interval
1170 * is fixed at this value.
1172 peer = newpeer(&rbufp->recv_srcadr, NULL, match_ep,
1173 MODE_CLIENT, hisversion, pkt->ppoll, pkt->ppoll,
1174 FLAG_BC_VOL | FLAG_IBURST | FLAG_PREEMPT, MDF_BCLNT,
1175 0, skeyid, sys_ident);
1178 return; /* ignore duplicate */
1181 if (skeyid > NTP_MAXKEY)
1182 crypto_recv(peer, rbufp);
1183 #endif /* AUTOKEY */
1185 return; /* hooray */
1188 * This is the first packet received from a symmetric active
1189 * peer. If the packet is authentic and the first he sent,
1190 * mobilize a passive association. If not, kiss the frog.
1196 * Do not respond if not the same group.
1198 if (group_test(groupname, sys_ident)) {
1202 #endif /* AUTOKEY */
1203 if (!AUTH(sys_authenticate | (restrict_mask &
1204 (RES_NOPEER | RES_DONTTRUST)), is_authentic)) {
1207 * If authenticated but cannot mobilize an
1208 * association, send a symmetric passive
1209 * response without mobilizing an association.
1210 * This is for drat broken Windows clients. See
1211 * Microsoft KB 875424 for preferred workaround.
1213 if (AUTH(restrict_mask & RES_DONTTRUST,
1215 fast_xmit(rbufp, MODE_PASSIVE, skeyid,
1217 return; /* hooray */
1219 if (is_authentic == AUTH_ERROR) {
1220 fast_xmit(rbufp, MODE_ACTIVE, 0,
1226 * If we got here, the packet isn't part of an
1227 * existing association, it isn't correctly
1228 * authenticated, and it didn't meet either of
1229 * the previous two special cases so we should
1230 * just drop it on the floor. For example,
1231 * crypto-NAKs (is_authentic == AUTH_CRYPTO)
1232 * will make it this far. This is just
1233 * debug-printed and not logged to avoid log
1236 DPRINTF(2, ("receive: at %ld refusing to mobilize passive association"
1237 " with unknown peer %s mode %d/%s:%s keyid %08x len %d auth %d\n",
1238 current_time, stoa(&rbufp->recv_srcadr),
1239 hismode, hm_str, am_str, skeyid,
1240 (authlen + has_mac), is_authentic));
1246 * Do not respond if synchronized and if stratum is
1247 * below the floor or at or above the ceiling. Note,
1248 * this allows an unsynchronized peer to synchronize to
1249 * us. It would be very strange if he did and then was
1250 * nipped, but that could only happen if we were
1251 * operating at the top end of the range. It also means
1252 * we will spin an ephemeral association in response to
1253 * MODE_ACTIVE KoDs, which will time out eventually.
1255 if ( hisleap != LEAP_NOTINSYNC
1256 && (hisstratum < sys_floor || hisstratum >= sys_ceiling)) {
1258 return; /* no help */
1262 * The message is correctly authenticated and allowed.
1263 * Mobilize a symmetric passive association.
1265 if ((peer = newpeer(&rbufp->recv_srcadr, NULL,
1266 rbufp->dstadr, MODE_PASSIVE, hisversion, pkt->ppoll,
1267 NTP_MAXDPOLL, 0, MDF_UCAST, 0, skeyid,
1268 sys_ident)) == NULL) {
1270 return; /* ignore duplicate */
1276 * Process regular packet. Nothing special.
1282 * Do not respond if not the same group.
1284 if (group_test(groupname, peer->ident)) {
1288 #endif /* AUTOKEY */
1292 * A passive packet matches a passive association. This is
1293 * usually the result of reconfiguring a client on the fly. As
1294 * this association might be legitimate and this packet an
1295 * attempt to deny service, just ignore it.
1302 * For everything else there is the bit bucket.
1311 * If the association is configured for Autokey, the packet must
1312 * have a public key ID; if not, the packet must have a
1315 if ( is_authentic != AUTH_CRYPTO
1316 && ( ((peer->flags & FLAG_SKEY) && skeyid <= NTP_MAXKEY)
1317 || (!(peer->flags & FLAG_SKEY) && skeyid > NTP_MAXKEY))) {
1321 #endif /* AUTOKEY */
1323 peer->flash &= ~PKT_TEST_MASK;
1324 if (peer->flags & FLAG_XBOGUS) {
1325 peer->flags &= ~FLAG_XBOGUS;
1326 peer->flash |= TEST3;
1330 * Next comes a rigorous schedule of timestamp checking. If the
1331 * transmit timestamp is zero, the server has not initialized in
1332 * interleaved modes or is horribly broken.
1334 if (L_ISZERO(&p_xmt)) {
1335 peer->flash |= TEST3; /* unsynch */
1338 * If the transmit timestamp duplicates a previous one, the
1339 * packet is a replay. This prevents the bad guys from replaying
1340 * the most recent packet, authenticated or not.
1342 } else if (L_ISEQU(&peer->xmt, &p_xmt)) {
1343 peer->flash |= TEST1; /* duplicate */
1348 * If this is a broadcast mode packet, skip further checking. If
1349 * an initial volley, bail out now and let the client do its
1350 * stuff. If the origin timestamp is nonzero, this is an
1351 * interleaved broadcast. so restart the protocol.
1353 } else if (hismode == MODE_BROADCAST) {
1354 if (!L_ISZERO(&p_org) && !(peer->flags & FLAG_XB)) {
1355 peer->flags |= FLAG_XB;
1357 peer->borg = rbufp->recv_time;
1358 report_event(PEVNT_XLEAVE, peer, NULL);
1363 * Basic mode checks:
1365 * If there is no origin timestamp, it's an initial packet.
1367 * Otherwise, check for bogus packet in basic mode.
1368 * If it is bogus, switch to interleaved mode and resynchronize,
1369 * but only after confirming the packet is not bogus in
1370 * symmetric interleaved mode.
1372 * This could also mean somebody is forging packets claiming to
1373 * be from us, attempting to cause our server to KoD us.
1375 } else if (peer->flip == 0) {
1376 if (0 < hisstratum && L_ISZERO(&p_org)) {
1378 } else if (!L_ISEQU(&p_org, &peer->aorg)) {
1380 peer->flash |= TEST2; /* bogus */
1382 "receive: Unexpected origin timestamp %#010x.%08x from %s xmt %#010x.%08x",
1383 ntohl(pkt->org.l_ui), ntohl(pkt->org.l_uf),
1384 ntoa(&peer->srcadr),
1385 ntohl(pkt->xmt.l_ui), ntohl(pkt->xmt.l_uf));
1386 if ( !L_ISZERO(&peer->dst)
1387 && L_ISEQU(&p_org, &peer->dst)) {
1388 /* Might be the start of an interleave */
1390 report_event(PEVNT_XLEAVE, peer, NULL);
1392 return; /* Bogus or possible interleave packet */
1398 * Check for valid nonzero timestamp fields.
1400 } else if (L_ISZERO(&p_org) || L_ISZERO(&p_rec) ||
1401 L_ISZERO(&peer->dst)) {
1402 peer->flash |= TEST3; /* unsynch */
1405 * Check for bogus packet in interleaved symmetric mode. This
1406 * can happen if a packet is lost, duplicated or crossed. If
1407 * found, flip and resynchronize.
1409 } else if ( !L_ISZERO(&peer->dst)
1410 && !L_ISEQU(&p_org, &peer->dst)) {
1412 peer->flags |= FLAG_XBOGUS;
1413 peer->flash |= TEST2; /* bogus */
1414 return; /* Bogus packet, we are done */
1418 * If this is a crypto_NAK, the server cannot authenticate a
1419 * client packet. The server might have just changed keys. Clear
1420 * the association and restart the protocol.
1422 if (is_authentic == AUTH_CRYPTO) {
1423 report_event(PEVNT_AUTH, peer, "crypto_NAK");
1424 peer->flash |= TEST5; /* bad auth */
1426 if (peer->flags & FLAG_PREEMPT) {
1432 peer_clear(peer, "AUTH");
1433 #endif /* AUTOKEY */
1437 * If the digest fails or it's missing for authenticated
1438 * associations, the client cannot authenticate a server
1439 * reply to a client packet previously sent. The loopback check
1440 * is designed to avoid a bait-and-switch attack, which was
1441 * possible in past versions. If symmetric modes, return a
1442 * crypto-NAK. The peer should restart the protocol.
1444 } else if (!AUTH(peer->keyid || has_mac ||
1445 (restrict_mask & RES_DONTTRUST), is_authentic)) {
1446 report_event(PEVNT_AUTH, peer, "digest");
1447 peer->flash |= TEST5; /* bad auth */
1450 && (hismode == MODE_ACTIVE || hismode == MODE_PASSIVE))
1451 fast_xmit(rbufp, MODE_ACTIVE, 0, restrict_mask);
1452 if (peer->flags & FLAG_PREEMPT) {
1458 peer_clear(peer, "AUTH");
1459 #endif /* AUTOKEY */
1464 * Update the state variables.
1466 if (peer->flip == 0) {
1467 if (hismode != MODE_BROADCAST)
1469 peer->dst = rbufp->recv_time;
1474 * Set the peer ppoll to the maximum of the packet ppoll and the
1475 * peer minpoll. If a kiss-o'-death, set the peer minpoll to
1476 * this maximum and advance the headway to give the sender some
1477 * headroom. Very intricate.
1481 * Check for any kiss codes. Note this is only used when a server
1482 * responds to a packet request
1485 kissCode = kiss_code_check(hisleap, hisstratum, hismode, pkt->refid);
1488 * Check to see if this is a RATE Kiss Code
1489 * Currently this kiss code will accept whatever poll
1490 * rate that the server sends
1492 peer->ppoll = max(peer->minpoll, pkt->ppoll);
1493 if (kissCode == RATEKISS) {
1494 peer->selbroken++; /* Increment the KoD count */
1495 report_event(PEVNT_RATE, peer, NULL);
1496 if (pkt->ppoll > peer->minpoll)
1497 peer->minpoll = peer->ppoll;
1498 peer->burst = peer->retry = 0;
1499 peer->throttle = (NTP_SHIFT + 1) * (1 << peer->minpoll);
1500 poll_update(peer, pkt->ppoll);
1501 return; /* kiss-o'-death */
1503 if (kissCode != NOKISS) {
1504 peer->selbroken++; /* Increment the KoD count */
1505 return; /* Drop any other kiss code packets */
1510 * That was hard and I am sweaty, but the packet is squeaky
1511 * clean. Get on with real work.
1513 peer->timereceived = current_time;
1514 if (is_authentic == AUTH_OK)
1515 peer->flags |= FLAG_AUTHENTIC;
1517 peer->flags &= ~FLAG_AUTHENTIC;
1521 * More autokey dance. The rules of the cha-cha are as follows:
1523 * 1. If there is no key or the key is not auto, do nothing.
1525 * 2. If this packet is in response to the one just previously
1526 * sent or from a broadcast server, do the extension fields.
1527 * Otherwise, assume bogosity and bail out.
1529 * 3. If an extension field contains a verified signature, it is
1530 * self-authenticated and we sit the dance.
1532 * 4. If this is a server reply, check only to see that the
1533 * transmitted key ID matches the received key ID.
1535 * 5. Check to see that one or more hashes of the current key ID
1536 * matches the previous key ID or ultimate original key ID
1537 * obtained from the broadcaster or symmetric peer. If no
1538 * match, sit the dance and call for new autokey values.
1540 * In case of crypto error, fire the orchestra, stop dancing and
1541 * restart the protocol.
1543 if (peer->flags & FLAG_SKEY) {
1545 * Decrement remaining autokey hashes. This isn't
1546 * perfect if a packet is lost, but results in no harm.
1548 ap = (struct autokey *)peer->recval.ptr;
1553 peer->flash |= TEST8;
1554 rval = crypto_recv(peer, rbufp);
1555 if (rval == XEVNT_OK) {
1558 if (rval == XEVNT_ERR) {
1559 report_event(PEVNT_RESTART, peer,
1561 peer_clear(peer, "CRYP");
1562 peer->flash |= TEST9; /* bad crypt */
1563 if (peer->flags & FLAG_PREEMPT)
1570 * If server mode, verify the receive key ID matches
1571 * the transmit key ID.
1573 if (hismode == MODE_SERVER) {
1574 if (skeyid == peer->keyid)
1575 peer->flash &= ~TEST8;
1578 * If an extension field is present, verify only that it
1579 * has been correctly signed. We don't need a sequence
1580 * check here, but the sequence continues.
1582 } else if (!(peer->flash & TEST8)) {
1583 peer->pkeyid = skeyid;
1586 * Now the fun part. Here, skeyid is the current ID in
1587 * the packet, pkeyid is the ID in the last packet and
1588 * tkeyid is the hash of skeyid. If the autokey values
1589 * have not been received, this is an automatic error.
1590 * If so, check that the tkeyid matches pkeyid. If not,
1591 * hash tkeyid and try again. If the number of hashes
1592 * exceeds the number remaining in the sequence, declare
1593 * a successful failure and refresh the autokey values.
1595 } else if (ap != NULL) {
1598 for (i = 0; ; i++) {
1599 if ( tkeyid == peer->pkeyid
1600 || tkeyid == ap->key) {
1601 peer->flash &= ~TEST8;
1602 peer->pkeyid = skeyid;
1611 tkeyid = session_key(
1612 &rbufp->recv_srcadr, dstadr_sin,
1615 if (peer->flash & TEST8)
1616 report_event(PEVNT_AUTH, peer, "keylist");
1618 if (!(peer->crypto & CRYPTO_FLAG_PROV)) /* test 9 */
1619 peer->flash |= TEST8; /* bad autokey */
1622 * The maximum lifetime of the protocol is about one
1623 * week before restarting the Autokey protocol to
1624 * refresh certificates and leapseconds values.
1626 if (current_time > peer->refresh) {
1627 report_event(PEVNT_RESTART, peer,
1629 peer_clear(peer, "TIME");
1633 #endif /* AUTOKEY */
1636 * The dance is complete and the flash bits have been lit. Toss
1637 * the packet over the fence for processing, which may light up
1640 process_packet(peer, pkt, rbufp->recv_length);
1643 * In interleaved mode update the state variables. Also adjust the
1644 * transmit phase to avoid crossover.
1646 if (peer->flip != 0) {
1648 peer->dst = rbufp->recv_time;
1649 if (peer->nextdate - current_time < (1U << min(peer->ppoll,
1659 * process_packet - Packet Procedure, a la Section 3.4.4 of the
1660 * specification. Or almost, at least. If we're in here we have a
1661 * reasonable expectation that we will be having a long term
1662 * relationship with this host.
1666 register struct peer *peer,
1667 register struct pkt *pkt,
1672 double p_offset, p_del, p_disp;
1673 l_fp p_rec, p_xmt, p_org, p_reftime, ci;
1674 u_char pmode, pleap, pversion, pstratum;
1675 char statstr[NTP_MAXSTRLEN];
1678 double etemp, ftemp, td;
1683 p_del = FPTOD(NTOHS_FP(pkt->rootdelay));
1685 p_disp = FPTOD(NTOHS_FP(pkt->rootdisp));
1686 NTOHL_FP(&pkt->reftime, &p_reftime);
1687 NTOHL_FP(&pkt->org, &p_org);
1688 NTOHL_FP(&pkt->rec, &p_rec);
1689 NTOHL_FP(&pkt->xmt, &p_xmt);
1690 pmode = PKT_MODE(pkt->li_vn_mode);
1691 pleap = PKT_LEAP(pkt->li_vn_mode);
1692 pversion = PKT_VERSION(pkt->li_vn_mode);
1693 pstratum = PKT_TO_STRATUM(pkt->stratum);
1696 * Capture the header values in the client/peer association..
1698 record_raw_stats(&peer->srcadr, peer->dstadr ?
1699 &peer->dstadr->sin : NULL,
1700 &p_org, &p_rec, &p_xmt, &peer->dst,
1701 pleap, pversion, pmode, pstratum, pkt->ppoll, pkt->precision,
1702 p_del, p_disp, pkt->refid);
1704 peer->stratum = min(pstratum, STRATUM_UNSPEC);
1705 peer->pmode = pmode;
1706 peer->precision = pkt->precision;
1707 peer->rootdelay = p_del;
1708 peer->rootdisp = p_disp;
1709 peer->refid = pkt->refid; /* network byte order */
1710 peer->reftime = p_reftime;
1713 * First, if either burst mode is armed, enable the burst.
1714 * Compute the headway for the next packet and delay if
1715 * necessary to avoid exceeding the threshold.
1717 if (peer->retry > 0) {
1720 peer->burst = min(1 << (peer->hpoll -
1721 peer->minpoll), NTP_SHIFT) - 1;
1723 peer->burst = NTP_IBURST - 1;
1724 if (peer->burst > 0)
1725 peer->nextdate = current_time;
1727 poll_update(peer, peer->hpoll);
1730 * Verify the server is synchronized; that is, the leap bits,
1731 * stratum and root distance are valid.
1733 if ( pleap == LEAP_NOTINSYNC /* test 6 */
1734 || pstratum < sys_floor || pstratum >= sys_ceiling)
1735 peer->flash |= TEST6; /* bad synch or strat */
1736 if (p_del / 2 + p_disp >= MAXDISPERSE) /* test 7 */
1737 peer->flash |= TEST7; /* bad header */
1740 * If any tests fail at this point, the packet is discarded.
1741 * Note that some flashers may have already been set in the
1742 * receive() routine.
1744 if (peer->flash & PKT_TEST_MASK) {
1745 peer->seldisptoolarge++;
1746 DPRINTF(1, ("packet: flash header %04x\n",
1752 * If the peer was previously unreachable, raise a trap. In any
1753 * case, mark it reachable.
1756 report_event(PEVNT_REACH, peer, NULL);
1757 peer->timereachable = current_time;
1762 * For a client/server association, calculate the clock offset,
1763 * roundtrip delay and dispersion. The equations are reordered
1764 * from the spec for more efficient use of temporaries. For a
1765 * broadcast association, offset the last measurement by the
1766 * computed delay during the client/server volley. Note the
1767 * computation of dispersion includes the system precision plus
1768 * that due to the frequency error since the origin time.
1770 * It is very important to respect the hazards of overflow. The
1771 * only permitted operation on raw timestamps is subtraction,
1772 * where the result is a signed quantity spanning from 68 years
1773 * in the past to 68 years in the future. To avoid loss of
1774 * precision, these calculations are done using 64-bit integer
1775 * arithmetic. However, the offset and delay calculations are
1776 * sums and differences of these first-order differences, which
1777 * if done using 64-bit integer arithmetic, would be valid over
1778 * only half that span. Since the typical first-order
1779 * differences are usually very small, they are converted to 64-
1780 * bit doubles and all remaining calculations done in floating-
1781 * double arithmetic. This preserves the accuracy while
1782 * retaining the 68-year span.
1784 * There are three interleaving schemes, basic, interleaved
1785 * symmetric and interleaved broadcast. The timestamps are
1786 * idioscyncratically different. See the onwire briefing/white
1787 * paper at www.eecis.udel.edu/~mills for details.
1789 * Interleaved symmetric mode
1790 * t1 = peer->aorg/borg, t2 = peer->rec, t3 = p_xmt,
1793 if (peer->flip != 0) {
1794 ci = p_xmt; /* t3 - t4 */
1795 L_SUB(&ci, &peer->dst);
1797 ci = p_rec; /* t2 - t1 */
1799 L_SUB(&ci, &peer->borg);
1801 L_SUB(&ci, &peer->aorg);
1804 p_offset = (t21 + t34) / 2.;
1805 if (p_del < 0 || p_del > 1.) {
1806 snprintf(statstr, sizeof(statstr),
1807 "t21 %.6f t34 %.6f", t21, t34);
1808 report_event(PEVNT_XERR, peer, statstr);
1815 } else if (peer->pmode == MODE_BROADCAST) {
1818 * Interleaved broadcast mode. Use interleaved timestamps.
1819 * t1 = peer->borg, t2 = p_org, t3 = p_org, t4 = aorg
1821 if (peer->flags & FLAG_XB) {
1822 ci = p_org; /* delay */
1823 L_SUB(&ci, &peer->aorg);
1825 ci = p_org; /* t2 - t1 */
1826 L_SUB(&ci, &peer->borg);
1829 peer->borg = peer->dst;
1830 if (t34 < 0 || t34 > 1.) {
1831 snprintf(statstr, sizeof(statstr),
1832 "offset %.6f delay %.6f", t21, t34);
1833 report_event(PEVNT_XERR, peer, statstr);
1840 * Basic broadcast - use direct timestamps.
1841 * t3 = p_xmt, t4 = peer->dst
1844 ci = p_xmt; /* t3 - t4 */
1845 L_SUB(&ci, &peer->dst);
1851 * When calibration is complete and the clock is
1852 * synchronized, the bias is calculated as the difference
1853 * between the unicast timestamp and the broadcast
1854 * timestamp. This works for both basic and interleaved
1857 if (FLAG_BC_VOL & peer->flags) {
1858 peer->flags &= ~FLAG_BC_VOL;
1859 peer->delay = fabs(peer->offset - p_offset) * 2;
1861 p_del = peer->delay;
1862 p_offset += p_del / 2;
1866 * Basic mode, otherwise known as the old fashioned way.
1868 * t1 = p_org, t2 = p_rec, t3 = p_xmt, t4 = peer->dst
1871 ci = p_xmt; /* t3 - t4 */
1872 L_SUB(&ci, &peer->dst);
1874 ci = p_rec; /* t2 - t1 */
1877 p_del = fabs(t21 - t34);
1878 p_offset = (t21 + t34) / 2.;
1880 p_del = max(p_del, LOGTOD(sys_precision));
1881 p_disp = LOGTOD(sys_precision) + LOGTOD(peer->precision) +
1886 * This code calculates the outbound and inbound data rates by
1887 * measuring the differences between timestamps at different
1888 * packet lengths. This is helpful in cases of large asymmetric
1889 * delays commonly experienced on deep space communication
1892 if (peer->t21_last > 0 && peer->t34_bytes > 0) {
1893 itemp = peer->t21_bytes - peer->t21_last;
1895 etemp = t21 - peer->t21;
1896 if (fabs(etemp) > 1e-6) {
1897 ftemp = itemp / etemp;
1902 itemp = len - peer->t34_bytes;
1904 etemp = -t34 - peer->t34;
1905 if (fabs(etemp) > 1e-6) {
1906 ftemp = itemp / etemp;
1914 * The following section compensates for different data rates on
1915 * the outbound (d21) and inbound (t34) directions. To do this,
1916 * it finds t such that r21 * t - r34 * (d - t) = 0, where d is
1917 * the roundtrip delay. Then it calculates the correction as a
1921 peer->t21_last = peer->t21_bytes;
1923 peer->t34_bytes = len;
1924 DPRINTF(2, ("packet: t21 %.9lf %d t34 %.9lf %d\n", peer->t21,
1925 peer->t21_bytes, peer->t34, peer->t34_bytes));
1926 if (peer->r21 > 0 && peer->r34 > 0 && p_del > 0) {
1927 if (peer->pmode != MODE_BROADCAST)
1928 td = (peer->r34 / (peer->r21 + peer->r34) -
1934 * Unfortunately, in many cases the errors are
1935 * unacceptable, so for the present the rates are not
1936 * used. In future, we might find conditions where the
1937 * calculations are useful, so this should be considered
1938 * a work in progress.
1942 DPRINTF(2, ("packet: del %.6lf r21 %.1lf r34 %.1lf %.6lf\n",
1943 p_del, peer->r21 / 1e3, peer->r34 / 1e3,
1949 * That was awesome. Now hand off to the clock filter.
1951 clock_filter(peer, p_offset + peer->bias, p_del, p_disp);
1954 * If we are in broadcast calibrate mode, return to broadcast
1955 * client mode when the client is fit and the autokey dance is
1958 if ( (FLAG_BC_VOL & peer->flags)
1959 && MODE_CLIENT == peer->hmode
1960 && !(TEST11 & peer_unfit(peer))) { /* distance exceeded */
1962 if (peer->flags & FLAG_SKEY) {
1963 if (!(~peer->crypto & CRYPTO_FLAG_ALL))
1964 peer->hmode = MODE_BCLIENT;
1966 peer->hmode = MODE_BCLIENT;
1968 #else /* !AUTOKEY follows */
1969 peer->hmode = MODE_BCLIENT;
1970 #endif /* !AUTOKEY */
1976 * clock_update - Called at system process update intervals.
1980 struct peer *peer /* peer structure pointer */
1985 #ifdef HAVE_LIBSCF_H
1987 #endif /* HAVE_LIBSCF_H */
1990 * Update the system state variables. We do this very carefully,
1991 * as the poll interval might need to be clamped differently.
1994 sys_epoch = peer->epoch;
1995 if (sys_poll < peer->minpoll)
1996 sys_poll = peer->minpoll;
1997 if (sys_poll > peer->maxpoll)
1998 sys_poll = peer->maxpoll;
1999 poll_update(peer, sys_poll);
2000 sys_stratum = min(peer->stratum + 1, STRATUM_UNSPEC);
2001 if ( peer->stratum == STRATUM_REFCLOCK
2002 || peer->stratum == STRATUM_UNSPEC)
2003 sys_refid = peer->refid;
2005 sys_refid = addr2refid(&peer->srcadr);
2007 * Root Dispersion (E) is defined (in RFC 5905) as:
2009 * E = p.epsilon_r + p.epsilon + p.psi + PHI*(s.t - p.t) + |THETA|
2012 * p.epsilon_r is the PollProc's root dispersion
2013 * p.epsilon is the PollProc's dispersion
2014 * p.psi is the PollProc's jitter
2015 * THETA is the combined offset
2017 * NB: Think Hard about where these numbers come from and
2018 * what they mean. When did peer->update happen? Has anything
2019 * interesting happened since then? What values are the most
2022 * DLM thinks this equation is probably the best of all worse choices.
2024 dtemp = peer->rootdisp
2027 + clock_phi * (current_time - peer->update)
2030 if (dtemp > sys_mindisp)
2031 sys_rootdisp = dtemp;
2033 sys_rootdisp = sys_mindisp;
2034 sys_rootdelay = peer->delay + peer->rootdelay;
2035 sys_reftime = peer->dst;
2037 DPRINTF(1, ("clock_update: at %lu sample %lu associd %d\n",
2038 current_time, peer->epoch, peer->associd));
2041 * Comes now the moment of truth. Crank the clock discipline and
2042 * see what comes out.
2044 switch (local_clock(peer, sys_offset)) {
2047 * Clock exceeds panic threshold. Life as we know it ends.
2050 #ifdef HAVE_LIBSCF_H
2052 * For Solaris enter the maintenance mode.
2054 if ((fmri = getenv("SMF_FMRI")) != NULL) {
2055 if (smf_maintain_instance(fmri, 0) < 0) {
2056 printf("smf_maintain_instance: %s\n",
2057 scf_strerror(scf_error()));
2061 * Sleep until SMF kills us.
2066 #endif /* HAVE_LIBSCF_H */
2071 * Clock was stepped. Flush all time values of all peers.
2075 set_sys_leap(LEAP_NOTINSYNC);
2076 sys_stratum = STRATUM_UNSPEC;
2077 memcpy(&sys_refid, "STEP", 4);
2080 L_CLR(&sys_reftime);
2081 sys_jitter = LOGTOD(sys_precision);
2082 leapsec_reset_frame();
2086 * Clock was slewed. Handle the leapsecond stuff.
2091 * If this is the first time the clock is set, reset the
2092 * leap bits. If crypto, the timer will goose the setup
2095 if (sys_leap == LEAP_NOTINSYNC) {
2096 set_sys_leap(LEAP_NOWARNING);
2100 #endif /* AUTOKEY */
2102 * If our parent process is waiting for the
2103 * first clock sync, send them home satisfied.
2105 #ifdef HAVE_WORKING_FORK
2106 if (waitsync_fd_to_close != -1) {
2107 close(waitsync_fd_to_close);
2108 waitsync_fd_to_close = -1;
2109 DPRINTF(1, ("notified parent --wait-sync is done\n"));
2111 #endif /* HAVE_WORKING_FORK */
2116 * If there is no leap second pending and the number of
2117 * survivor leap bits is greater than half the number of
2118 * survivors, try to schedule a leap for the end of the
2119 * current month. (This only works if no leap second for
2120 * that range is in the table, so doing this more than
2121 * once is mostly harmless.)
2123 if (leapsec == LSPROX_NOWARN) {
2124 if ( leap_vote_ins > leap_vote_del
2125 && leap_vote_ins > sys_survivors / 2) {
2127 leapsec_add_dyn(TRUE, now.l_ui, NULL);
2129 if ( leap_vote_del > leap_vote_ins
2130 && leap_vote_del > sys_survivors / 2) {
2132 leapsec_add_dyn(FALSE, now.l_ui, NULL);
2138 * Popcorn spike or step threshold exceeded. Pretend it never
2148 * poll_update - update peer poll interval
2152 struct peer *peer, /* peer structure pointer */
2160 * This routine figures out when the next poll should be sent.
2161 * That turns out to be wickedly complicated. One problem is
2162 * that sometimes the time for the next poll is in the past when
2163 * the poll interval is reduced. We watch out for races here
2164 * between the receive process and the poll process.
2166 * Clamp the poll interval between minpoll and maxpoll.
2168 hpoll = max(min(peer->maxpoll, mpoll), peer->minpoll);
2172 * If during the crypto protocol the poll interval has changed,
2173 * the lifetimes in the key list are probably bogus. Purge the
2174 * the key list and regenerate it later.
2176 if ((peer->flags & FLAG_SKEY) && hpoll != peer->hpoll)
2178 #endif /* AUTOKEY */
2179 peer->hpoll = hpoll;
2182 * There are three variables important for poll scheduling, the
2183 * current time (current_time), next scheduled time (nextdate)
2184 * and the earliest time (utemp). The earliest time is 2 s
2185 * seconds, but could be more due to rate management. When
2186 * sending in a burst, use the earliest time. When not in a
2187 * burst but with a reply pending, send at the earliest time
2188 * unless the next scheduled time has not advanced. This can
2189 * only happen if multiple replies are pending in the same
2190 * response interval. Otherwise, send at the later of the next
2191 * scheduled time and the earliest time.
2193 * Now we figure out if there is an override. If a burst is in
2194 * progress and we get called from the receive process, just
2195 * slink away. If called from the poll process, delay 1 s for a
2196 * reference clock, otherwise 2 s.
2198 utemp = current_time + max(peer->throttle - (NTP_SHIFT - 1) *
2199 (1 << peer->minpoll), ntp_minpkt);
2200 if (peer->burst > 0) {
2201 if (peer->nextdate > current_time)
2204 else if (peer->flags & FLAG_REFCLOCK)
2205 peer->nextdate = current_time + RESP_DELAY;
2206 #endif /* REFCLOCK */
2208 peer->nextdate = utemp;
2212 * If a burst is not in progress and a crypto response message
2213 * is pending, delay 2 s, but only if this is a new interval.
2215 } else if (peer->cmmd != NULL) {
2216 if (peer->nextdate > current_time) {
2217 if (peer->nextdate + ntp_minpkt != utemp)
2218 peer->nextdate = utemp;
2220 peer->nextdate = utemp;
2222 #endif /* AUTOKEY */
2225 * The ordinary case. If a retry, use minpoll; if unreachable,
2226 * use host poll; otherwise, use the minimum of host and peer
2227 * polls; In other words, oversampling is okay but
2228 * understampling is evil. Use the maximum of this value and the
2229 * headway. If the average headway is greater than the headway
2230 * threshold, increase the headway by the minimum interval.
2233 if (peer->retry > 0)
2234 hpoll = peer->minpoll;
2235 else if (!(peer->reach))
2236 hpoll = peer->hpoll;
2238 hpoll = min(peer->ppoll, peer->hpoll);
2240 if (peer->flags & FLAG_REFCLOCK)
2243 #endif /* REFCLOCK */
2244 next = ((0x1000UL | (ntp_random() & 0x0ff)) <<
2246 next += peer->outdate;
2248 peer->nextdate = next;
2250 peer->nextdate = utemp;
2251 if (peer->throttle > (1 << peer->minpoll))
2252 peer->nextdate += ntp_minpkt;
2254 DPRINTF(2, ("poll_update: at %lu %s poll %d burst %d retry %d head %d early %lu next %lu\n",
2255 current_time, ntoa(&peer->srcadr), peer->hpoll,
2256 peer->burst, peer->retry, peer->throttle,
2257 utemp - current_time, peer->nextdate -
2263 * peer_clear - clear peer filter registers. See Section 3.4.8 of the
2268 struct peer *peer, /* peer structure */
2269 const char *ident /* tally lights */
2276 * If cryptographic credentials have been acquired, toss them to
2277 * Valhalla. Note that autokeys are ephemeral, in that they are
2278 * tossed immediately upon use. Therefore, the keylist can be
2279 * purged anytime without needing to preserve random keys. Note
2280 * that, if the peer is purged, the cryptographic variables are
2281 * purged, too. This makes it much harder to sneak in some
2282 * unauthenticated data in the clock filter.
2285 if (peer->iffval != NULL)
2286 BN_free(peer->iffval);
2287 value_free(&peer->cookval);
2288 value_free(&peer->recval);
2289 value_free(&peer->encrypt);
2290 value_free(&peer->sndval);
2291 if (peer->cmmd != NULL)
2293 if (peer->subject != NULL)
2294 free(peer->subject);
2295 if (peer->issuer != NULL)
2297 #endif /* AUTOKEY */
2300 * Clear all values, including the optional crypto values above.
2302 memset(CLEAR_TO_ZERO(peer), 0, LEN_CLEAR_TO_ZERO(peer));
2303 peer->ppoll = peer->maxpoll;
2304 peer->hpoll = peer->minpoll;
2305 peer->disp = MAXDISPERSE;
2306 peer->flash = peer_unfit(peer);
2307 peer->jitter = LOGTOD(sys_precision);
2310 * If interleave mode, initialize the alternate origin switch.
2312 if (peer->flags & FLAG_XLEAVE)
2314 for (u = 0; u < NTP_SHIFT; u++) {
2315 peer->filter_order[u] = u;
2316 peer->filter_disp[u] = MAXDISPERSE;
2319 if (!(peer->flags & FLAG_REFCLOCK)) {
2321 peer->leap = LEAP_NOTINSYNC;
2322 peer->stratum = STRATUM_UNSPEC;
2323 memcpy(&peer->refid, ident, 4);
2329 * During initialization use the association count to spread out
2330 * the polls at one-second intervals. Passive associations'
2331 * first poll is delayed by the "discard minimum" to avoid rate
2332 * limiting. Other post-startup new or cleared associations
2333 * randomize the first poll over the minimum poll interval to
2336 peer->nextdate = peer->update = peer->outdate = current_time;
2338 peer->nextdate += peer_associations;
2339 } else if (MODE_PASSIVE == peer->hmode) {
2340 peer->nextdate += ntp_minpkt;
2342 peer->nextdate += ntp_random() % peer->minpoll;
2345 peer->refresh = current_time + (1 << NTP_REFRESH);
2346 #endif /* AUTOKEY */
2347 DPRINTF(1, ("peer_clear: at %ld next %ld associd %d refid %s\n",
2348 current_time, peer->nextdate, peer->associd,
2354 * clock_filter - add incoming clock sample to filter register and run
2355 * the filter procedure to find the best sample.
2359 struct peer *peer, /* peer structure pointer */
2360 double sample_offset, /* clock offset */
2361 double sample_delay, /* roundtrip delay */
2362 double sample_disp /* dispersion */
2365 double dst[NTP_SHIFT]; /* distance vector */
2366 int ord[NTP_SHIFT]; /* index vector */
2368 double dtemp, etemp;
2372 * A sample consists of the offset, delay, dispersion and epoch
2373 * of arrival. The offset and delay are determined by the on-
2374 * wire protocol. The dispersion grows from the last outbound
2375 * packet to the arrival of this one increased by the sum of the
2376 * peer precision and the system precision as required by the
2377 * error budget. First, shift the new arrival into the shift
2378 * register discarding the oldest one.
2380 j = peer->filter_nextpt;
2381 peer->filter_offset[j] = sample_offset;
2382 peer->filter_delay[j] = sample_delay;
2383 peer->filter_disp[j] = sample_disp;
2384 peer->filter_epoch[j] = current_time;
2385 j = (j + 1) % NTP_SHIFT;
2386 peer->filter_nextpt = j;
2389 * Update dispersions since the last update and at the same
2390 * time initialize the distance and index lists. Since samples
2391 * become increasingly uncorrelated beyond the Allan intercept,
2392 * only under exceptional cases will an older sample be used.
2393 * Therefore, the distance list uses a compound metric. If the
2394 * dispersion is greater than the maximum dispersion, clamp the
2395 * distance at that value. If the time since the last update is
2396 * less than the Allan intercept use the delay; otherwise, use
2397 * the sum of the delay and dispersion.
2399 dtemp = clock_phi * (current_time - peer->update);
2400 peer->update = current_time;
2401 for (i = NTP_SHIFT - 1; i >= 0; i--) {
2403 peer->filter_disp[j] += dtemp;
2404 if (peer->filter_disp[j] >= MAXDISPERSE) {
2405 peer->filter_disp[j] = MAXDISPERSE;
2406 dst[i] = MAXDISPERSE;
2407 } else if (peer->update - peer->filter_epoch[j] >
2408 (u_long)ULOGTOD(allan_xpt)) {
2409 dst[i] = peer->filter_delay[j] +
2410 peer->filter_disp[j];
2412 dst[i] = peer->filter_delay[j];
2415 j = (j + 1) % NTP_SHIFT;
2419 * If the clock has stabilized, sort the samples by distance.
2421 if (freq_cnt == 0) {
2422 for (i = 1; i < NTP_SHIFT; i++) {
2423 for (j = 0; j < i; j++) {
2424 if (dst[j] > dst[i]) {
2437 * Copy the index list to the association structure so ntpq
2438 * can see it later. Prune the distance list to leave only
2439 * samples less than the maximum dispersion, which disfavors
2440 * uncorrelated samples older than the Allan intercept. To
2441 * further improve the jitter estimate, of the remainder leave
2442 * only samples less than the maximum distance, but keep at
2443 * least two samples for jitter calculation.
2446 for (i = 0; i < NTP_SHIFT; i++) {
2447 peer->filter_order[i] = (u_char) ord[i];
2448 if ( dst[i] >= MAXDISPERSE
2449 || (m >= 2 && dst[i] >= sys_maxdist))
2455 * Compute the dispersion and jitter. The dispersion is weighted
2456 * exponentially by NTP_FWEIGHT (0.5) so it is normalized close
2457 * to 1.0. The jitter is the RMS differences relative to the
2458 * lowest delay sample.
2460 peer->disp = peer->jitter = 0;
2462 for (i = NTP_SHIFT - 1; i >= 0; i--) {
2464 peer->disp = NTP_FWEIGHT * (peer->disp +
2465 peer->filter_disp[j]);
2467 peer->jitter += DIFF(peer->filter_offset[j],
2468 peer->filter_offset[k]);
2472 * If no acceptable samples remain in the shift register,
2473 * quietly tiptoe home leaving only the dispersion. Otherwise,
2474 * save the offset, delay and jitter. Note the jitter must not
2475 * be less than the precision.
2481 etemp = fabs(peer->offset - peer->filter_offset[k]);
2482 peer->offset = peer->filter_offset[k];
2483 peer->delay = peer->filter_delay[k];
2485 peer->jitter /= m - 1;
2486 peer->jitter = max(SQRT(peer->jitter), LOGTOD(sys_precision));
2489 * If the the new sample and the current sample are both valid
2490 * and the difference between their offsets exceeds CLOCK_SGATE
2491 * (3) times the jitter and the interval between them is less
2492 * than twice the host poll interval, consider the new sample
2493 * a popcorn spike and ignore it.
2495 if ( peer->disp < sys_maxdist
2496 && peer->filter_disp[k] < sys_maxdist
2497 && etemp > CLOCK_SGATE * peer->jitter
2498 && peer->filter_epoch[k] - peer->epoch
2499 < 2. * ULOGTOD(peer->hpoll)) {
2500 snprintf(tbuf, sizeof(tbuf), "%.6f s", etemp);
2501 report_event(PEVNT_POPCORN, peer, tbuf);
2506 * A new minimum sample is useful only if it is later than the
2507 * last one used. In this design the maximum lifetime of any
2508 * sample is not greater than eight times the poll interval, so
2509 * the maximum interval between minimum samples is eight
2512 if (peer->filter_epoch[k] <= peer->epoch) {
2513 DPRINTF(2, ("clock_filter: old sample %lu\n", current_time -
2514 peer->filter_epoch[k]));
2517 peer->epoch = peer->filter_epoch[k];
2520 * The mitigated sample statistics are saved for later
2521 * processing. If not synchronized or not in a burst, tickle the
2522 * clock select algorithm.
2524 record_peer_stats(&peer->srcadr, ctlpeerstatus(peer),
2525 peer->offset, peer->delay, peer->disp, peer->jitter);
2526 DPRINTF(1, ("clock_filter: n %d off %.6f del %.6f dsp %.6f jit %.6f\n",
2527 m, peer->offset, peer->delay, peer->disp,
2529 if (peer->burst == 0 || sys_leap == LEAP_NOTINSYNC)
2535 * clock_select - find the pick-of-the-litter clock
2537 * LOCKCLOCK: (1) If the local clock is the prefer peer, it will always
2538 * be enabled, even if declared falseticker, (2) only the prefer peer
2539 * can be selected as the system peer, (3) if the external source is
2540 * down, the system leap bits are set to 11 and the stratum set to
2554 double orphmet = 2.0 * U_INT32_MAX; /* 2x is greater than */
2555 struct endpoint endp;
2556 struct peer *osys_peer;
2557 struct peer *sys_prefer = NULL; /* prefer peer */
2558 struct peer *typesystem = NULL;
2559 struct peer *typeorphan = NULL;
2561 struct peer *typeacts = NULL;
2562 struct peer *typelocal = NULL;
2563 struct peer *typepps = NULL;
2564 #endif /* REFCLOCK */
2565 static struct endpoint *endpoint = NULL;
2566 static int *indx = NULL;
2567 static peer_select *peers = NULL;
2568 static u_int endpoint_size = 0;
2569 static u_int peers_size = 0;
2570 static u_int indx_size = 0;
2574 * Initialize and create endpoint, index and peer lists big
2575 * enough to handle all associations.
2577 osys_peer = sys_peer;
2580 set_sys_leap(LEAP_NOTINSYNC);
2581 sys_stratum = STRATUM_UNSPEC;
2582 memcpy(&sys_refid, "DOWN", 4);
2583 #endif /* LOCKCLOCK */
2586 * Allocate dynamic space depending on the number of
2590 for (peer = peer_list; peer != NULL; peer = peer->p_link)
2592 endpoint_size = ALIGNED_SIZE(nlist * 2 * sizeof(*endpoint));
2593 peers_size = ALIGNED_SIZE(nlist * sizeof(*peers));
2594 indx_size = ALIGNED_SIZE(nlist * 2 * sizeof(*indx));
2595 octets = endpoint_size + peers_size + indx_size;
2596 endpoint = erealloc(endpoint, octets);
2597 peers = INC_ALIGNED_PTR(endpoint, endpoint_size);
2598 indx = INC_ALIGNED_PTR(peers, peers_size);
2601 * Initially, we populate the island with all the rifraff peers
2602 * that happen to be lying around. Those with seriously
2603 * defective clocks are immediately booted off the island. Then,
2604 * the falsetickers are culled and put to sea. The truechimers
2605 * remaining are subject to repeated rounds where the most
2606 * unpopular at each round is kicked off. When the population
2607 * has dwindled to sys_minclock, the survivors split a million
2608 * bucks and collectively crank the chimes.
2610 nlist = nl2 = 0; /* none yet */
2611 for (peer = peer_list; peer != NULL; peer = peer->p_link) {
2612 peer->new_status = CTL_PST_SEL_REJECT;
2615 * Leave the island immediately if the peer is
2616 * unfit to synchronize.
2618 if (peer_unfit(peer))
2622 * If this peer is an orphan parent, elect the
2623 * one with the lowest metric defined as the
2624 * IPv4 address or the first 64 bits of the
2625 * hashed IPv6 address. To ensure convergence
2626 * on the same selected orphan, consider as
2627 * well that this system may have the lowest
2628 * metric and be the orphan parent. If this
2629 * system wins, sys_peer will be NULL to trigger
2630 * orphan mode in timer().
2632 if (peer->stratum == sys_orphan) {
2636 if (peer->dstadr != NULL)
2637 localmet = ntohl(peer->dstadr->addr_refid);
2639 localmet = U_INT32_MAX;
2640 peermet = ntohl(addr2refid(&peer->srcadr));
2641 if (peermet < localmet && peermet < orphmet) {
2649 * If this peer could have the orphan parent
2650 * as a synchronization ancestor, exclude it
2651 * from selection to avoid forming a
2652 * synchronization loop within the orphan mesh,
2653 * triggering stratum climb to infinity
2654 * instability. Peers at stratum higher than
2655 * the orphan stratum could have the orphan
2656 * parent in ancestry so are excluded.
2657 * See http://bugs.ntp.org/2050
2659 if (peer->stratum > sys_orphan)
2663 * The following are special cases. We deal
2666 if (!(peer->flags & FLAG_PREFER)) {
2667 switch (peer->refclktype) {
2668 case REFCLK_LOCALCLOCK:
2669 if ( current_time > orphwait
2670 && typelocal == NULL)
2675 if ( current_time > orphwait
2676 && typeacts == NULL)
2681 #endif /* REFCLOCK */
2684 * If we get this far, the peer can stay on the
2685 * island, but does not yet have the immunity
2688 peer->new_status = CTL_PST_SEL_SANE;
2689 f = root_distance(peer);
2690 peers[nlist].peer = peer;
2691 peers[nlist].error = peer->jitter;
2692 peers[nlist].synch = f;
2696 * Insert each interval endpoint on the unsorted
2700 endpoint[nl2].type = -1; /* lower end */
2701 endpoint[nl2].val = e - f;
2703 endpoint[nl2].type = 1; /* upper end */
2704 endpoint[nl2].val = e + f;
2708 * Construct sorted indx[] of endpoint[] indexes ordered by
2711 for (i = 0; i < nl2; i++)
2713 for (i = 0; i < nl2; i++) {
2714 endp = endpoint[indx[i]];
2717 for (j = i + 1; j < nl2; j++) {
2718 endp = endpoint[indx[j]];
2730 for (i = 0; i < nl2; i++)
2731 DPRINTF(3, ("select: endpoint %2d %.6f\n",
2732 endpoint[indx[i]].type, endpoint[indx[i]].val));
2735 * This is the actual algorithm that cleaves the truechimers
2736 * from the falsetickers. The original algorithm was described
2737 * in Keith Marzullo's dissertation, but has been modified for
2740 * Briefly put, we first assume there are no falsetickers, then
2741 * scan the candidate list first from the low end upwards and
2742 * then from the high end downwards. The scans stop when the
2743 * number of intersections equals the number of candidates less
2744 * the number of falsetickers. If this doesn't happen for a
2745 * given number of falsetickers, we bump the number of
2746 * falsetickers and try again. If the number of falsetickers
2747 * becomes equal to or greater than half the number of
2748 * candidates, the Albanians have won the Byzantine wars and
2749 * correct synchronization is not possible.
2751 * Here, nlist is the number of candidates and allow is the
2752 * number of falsetickers. Upon exit, the truechimers are the
2753 * survivors with offsets not less than low and not greater than
2754 * high. There may be none of them.
2758 for (allow = 0; 2 * allow < nlist; allow++) {
2761 * Bound the interval (low, high) as the smallest
2762 * interval containing points from the most sources.
2765 for (i = 0; i < nl2; i++) {
2766 low = endpoint[indx[i]].val;
2767 n -= endpoint[indx[i]].type;
2768 if (n >= nlist - allow)
2772 for (j = nl2 - 1; j >= 0; j--) {
2773 high = endpoint[indx[j]].val;
2774 n += endpoint[indx[j]].type;
2775 if (n >= nlist - allow)
2780 * If an interval containing truechimers is found, stop.
2781 * If not, increase the number of falsetickers and go
2789 * Clustering algorithm. Whittle candidate list of falsetickers,
2790 * who leave the island immediately. The TRUE peer is always a
2791 * truechimer. We must leave at least one peer to collect the
2794 * We assert the correct time is contained in the interval, but
2795 * the best offset estimate for the interval might not be
2796 * contained in the interval. For this purpose, a truechimer is
2797 * defined as the midpoint of an interval that overlaps the
2798 * intersection interval.
2801 for (i = 0; i < nlist; i++) {
2804 peer = peers[i].peer;
2807 || peer->offset + h < low
2808 || peer->offset - h > high
2809 ) && !(peer->flags & FLAG_TRUE))
2814 * Eligible PPS peers must survive the intersection
2815 * algorithm. Use the first one found, but don't
2816 * include any of them in the cluster population.
2818 if (peer->flags & FLAG_PPS) {
2819 if (typepps == NULL)
2821 if (!(peer->flags & FLAG_TSTAMP_PPS))
2824 #endif /* REFCLOCK */
2827 peers[j] = peers[i];
2833 * If no survivors remain at this point, check if the modem
2834 * driver, local driver or orphan parent in that order. If so,
2835 * nominate the first one found as the only survivor.
2836 * Otherwise, give up and leave the island to the rats.
2840 peers[0].synch = sys_mindisp;
2842 if (typeacts != NULL) {
2843 peers[0].peer = typeacts;
2845 } else if (typelocal != NULL) {
2846 peers[0].peer = typelocal;
2849 #endif /* REFCLOCK */
2850 if (typeorphan != NULL) {
2851 peers[0].peer = typeorphan;
2857 * Mark the candidates at this point as truechimers.
2859 for (i = 0; i < nlist; i++) {
2860 peers[i].peer->new_status = CTL_PST_SEL_SELCAND;
2861 DPRINTF(2, ("select: survivor %s %f\n",
2862 stoa(&peers[i].peer->srcadr), peers[i].synch));
2866 * Now, vote outliers off the island by select jitter weighted
2867 * by root distance. Continue voting as long as there are more
2868 * than sys_minclock survivors and the select jitter of the peer
2869 * with the worst metric is greater than the minimum peer
2870 * jitter. Stop if we are about to discard a TRUE or PREFER
2871 * peer, who of course have the immunity idol.
2878 for (i = 0; i < nlist; i++) {
2879 if (peers[i].error < d)
2881 peers[i].seljit = 0;
2884 for (j = 0; j < nlist; j++)
2885 f += DIFF(peers[j].peer->offset,
2886 peers[i].peer->offset);
2887 peers[i].seljit = SQRT(f / (nlist - 1));
2889 if (peers[i].seljit * peers[i].synch > e) {
2890 g = peers[i].seljit;
2891 e = peers[i].seljit * peers[i].synch;
2895 g = max(g, LOGTOD(sys_precision));
2896 if ( nlist <= max(1, sys_minclock)
2898 || ((FLAG_TRUE | FLAG_PREFER) & peers[k].peer->flags))
2901 DPRINTF(3, ("select: drop %s seljit %.6f jit %.6f\n",
2902 ntoa(&peers[k].peer->srcadr), g, d));
2903 if (nlist > sys_maxclock)
2904 peers[k].peer->new_status = CTL_PST_SEL_EXCESS;
2905 for (j = k + 1; j < nlist; j++)
2906 peers[j - 1] = peers[j];
2911 * What remains is a list usually not greater than sys_minclock
2912 * peers. Note that unsynchronized peers cannot survive this
2913 * far. Count and mark these survivors.
2915 * While at it, count the number of leap warning bits found.
2916 * This will be used later to vote the system leap warning bit.
2917 * If a leap warning bit is found on a reference clock, the vote
2920 * Choose the system peer using a hybrid metric composed of the
2921 * selection jitter scaled by the root distance augmented by
2922 * stratum scaled by sys_mindisp (.001 by default). The goal of
2923 * the small stratum factor is to avoid clockhop between a
2924 * reference clock and a network peer which has a refclock and
2925 * is using an older ntpd, which does not floor sys_rootdisp at
2928 * In contrast, ntpd 4.2.6 and earlier used stratum primarily
2929 * in selecting the system peer, using a weight of 1 second of
2930 * additional root distance per stratum. This heavy bias is no
2931 * longer appropriate, as the scaled root distance provides a
2932 * more rational metric carrying the cumulative error budget.
2938 for (i = 0; i < nlist; i++) {
2939 peer = peers[i].peer;
2941 peer->new_status = CTL_PST_SEL_SYNCCAND;
2943 if (peer->leap == LEAP_ADDSECOND) {
2944 if (peer->flags & FLAG_REFCLOCK)
2945 leap_vote_ins = nlist;
2946 else if (leap_vote_ins < nlist)
2949 if (peer->leap == LEAP_DELSECOND) {
2950 if (peer->flags & FLAG_REFCLOCK)
2951 leap_vote_del = nlist;
2952 else if (leap_vote_del < nlist)
2955 if (peer->flags & FLAG_PREFER)
2957 speermet = peers[i].seljit * peers[i].synch +
2958 peer->stratum * sys_mindisp;
2966 * Unless there are at least sys_misane survivors, leave the
2967 * building dark. Otherwise, do a clockhop dance. Ordinarily,
2968 * use the selected survivor speer. However, if the current
2969 * system peer is not speer, stay with the current system peer
2970 * as long as it doesn't get too old or too ugly.
2972 if (nlist > 0 && nlist >= sys_minsane) {
2975 typesystem = peers[speer].peer;
2976 if (osys_peer == NULL || osys_peer == typesystem) {
2978 } else if ((x = fabs(typesystem->offset -
2979 osys_peer->offset)) < sys_mindisp) {
2980 if (sys_clockhop == 0)
2981 sys_clockhop = sys_mindisp;
2984 DPRINTF(1, ("select: clockhop %d %.6f %.6f\n",
2985 j, x, sys_clockhop));
2986 if (fabs(x) < sys_clockhop)
2987 typesystem = osys_peer;
2996 * Mitigation rules of the game. We have the pick of the
2997 * litter in typesystem if any survivors are left. If
2998 * there is a prefer peer, use its offset and jitter.
2999 * Otherwise, use the combined offset and jitter of all kitters.
3001 if (typesystem != NULL) {
3002 if (sys_prefer == NULL) {
3003 typesystem->new_status = CTL_PST_SEL_SYSPEER;
3004 clock_combine(peers, sys_survivors, speer);
3006 typesystem = sys_prefer;
3008 typesystem->new_status = CTL_PST_SEL_SYSPEER;
3009 sys_offset = typesystem->offset;
3010 sys_jitter = typesystem->jitter;
3012 DPRINTF(1, ("select: combine offset %.9f jitter %.9f\n",
3013 sys_offset, sys_jitter));
3017 * If a PPS driver is lit and the combined offset is less than
3018 * 0.4 s, select the driver as the PPS peer and use its offset
3019 * and jitter. However, if this is the atom driver, use it only
3020 * if there is a prefer peer or there are no survivors and none
3023 if ( typepps != NULL
3024 && fabs(sys_offset) < 0.4
3025 && ( typepps->refclktype != REFCLK_ATOM_PPS
3026 || ( typepps->refclktype == REFCLK_ATOM_PPS
3027 && ( sys_prefer != NULL
3028 || (typesystem == NULL && sys_minsane == 0))))) {
3029 typesystem = typepps;
3031 typesystem->new_status = CTL_PST_SEL_PPS;
3032 sys_offset = typesystem->offset;
3033 sys_jitter = typesystem->jitter;
3034 DPRINTF(1, ("select: pps offset %.9f jitter %.9f\n",
3035 sys_offset, sys_jitter));
3037 #endif /* REFCLOCK */
3040 * If there are no survivors at this point, there is no
3041 * system peer. If so and this is an old update, keep the
3042 * current statistics, but do not update the clock.
3044 if (typesystem == NULL) {
3045 if (osys_peer != NULL) {
3046 if (sys_orphwait > 0)
3047 orphwait = current_time + sys_orphwait;
3048 report_event(EVNT_NOPEER, NULL, NULL);
3051 for (peer = peer_list; peer != NULL; peer = peer->p_link)
3052 peer->status = peer->new_status;
3057 * Do not use old data, as this may mess up the clock discipline
3060 if (typesystem->epoch <= sys_epoch)
3064 * We have found the alpha male. Wind the clock.
3066 if (osys_peer != typesystem)
3067 report_event(PEVNT_NEWPEER, typesystem, NULL);
3068 for (peer = peer_list; peer != NULL; peer = peer->p_link)
3069 peer->status = peer->new_status;
3070 clock_update(typesystem);
3076 peer_select * peers, /* survivor list */
3077 int npeers, /* number of survivors */
3078 int syspeer /* index of sys.peer */
3085 for (i = 0; i < npeers; i++) {
3086 x = 1. / peers[i].synch;
3088 z += x * peers[i].peer->offset;
3089 w += x * DIFF(peers[i].peer->offset,
3090 peers[syspeer].peer->offset);
3093 sys_jitter = SQRT(w / y + SQUARE(peers[syspeer].seljit));
3098 * root_distance - compute synchronization distance from peer to root
3102 struct peer *peer /* peer structure pointer */
3108 * Root Distance (LAMBDA) is defined as:
3109 * (delta + DELTA)/2 + epsilon + EPSILON + phi
3112 * delta is the round-trip delay
3113 * DELTA is the root delay
3114 * epsilon is the remote server precision + local precision
3115 * + (15 usec each second)
3116 * EPSILON is the root dispersion
3117 * phi is the peer jitter statistic
3119 * NB: Think hard about why we are using these values, and what
3120 * the alternatives are, and the various pros/cons.
3122 * DLM thinks these are probably the best choices from any of the
3123 * other worse choices.
3125 dtemp = (peer->delay + peer->rootdelay) / 2
3126 + LOGTOD(peer->precision)
3127 + LOGTOD(sys_precision)
3128 + clock_phi * (current_time - peer->update)
3132 * Careful squeak here. The value returned must be greater than
3133 * the minimum root dispersion in order to avoid clockhop with
3134 * highly precise reference clocks. Note that the root distance
3135 * cannot exceed the sys_maxdist, as this is the cutoff by the
3136 * selection algorithm.
3138 if (dtemp < sys_mindisp)
3139 dtemp = sys_mindisp;
3145 * peer_xmit - send packet for persistent association.
3149 struct peer *peer /* peer structure pointer */
3152 struct pkt xpkt; /* transmit packet */
3153 size_t sendlen, authlen;
3154 keyid_t xkeyid = 0; /* transmit key ID */
3155 l_fp xmt_tx, xmt_ty;
3157 if (!peer->dstadr) /* drop peers without interface */
3160 xpkt.li_vn_mode = PKT_LI_VN_MODE(sys_leap, peer->version,
3162 xpkt.stratum = STRATUM_TO_PKT(sys_stratum);
3163 xpkt.ppoll = peer->hpoll;
3164 xpkt.precision = sys_precision;
3165 xpkt.refid = sys_refid;
3166 xpkt.rootdelay = HTONS_FP(DTOFP(sys_rootdelay));
3167 xpkt.rootdisp = HTONS_FP(DTOUFP(sys_rootdisp));
3168 HTONL_FP(&sys_reftime, &xpkt.reftime);
3169 HTONL_FP(&peer->rec, &xpkt.org);
3170 HTONL_FP(&peer->dst, &xpkt.rec);
3173 * If the received packet contains a MAC, the transmitted packet
3174 * is authenticated and contains a MAC. If not, the transmitted
3175 * packet is not authenticated.
3177 * It is most important when autokey is in use that the local
3178 * interface IP address be known before the first packet is
3179 * sent. Otherwise, it is not possible to compute a correct MAC
3180 * the recipient will accept. Thus, the I/O semantics have to do
3181 * a little more work. In particular, the wildcard interface
3182 * might not be usable.
3184 sendlen = LEN_PKT_NOMAC;
3187 !(peer->flags & FLAG_SKEY) &&
3188 #endif /* !AUTOKEY */
3192 * Transmit a-priori timestamps
3194 get_systime(&xmt_tx);
3195 if (peer->flip == 0) { /* basic mode */
3196 peer->aorg = xmt_tx;
3197 HTONL_FP(&xmt_tx, &xpkt.xmt);
3198 } else { /* interleaved modes */
3199 if (peer->hmode == MODE_BROADCAST) { /* bcst */
3200 HTONL_FP(&xmt_tx, &xpkt.xmt);
3202 HTONL_FP(&peer->borg,
3205 HTONL_FP(&peer->aorg,
3207 } else { /* symmetric */
3209 HTONL_FP(&peer->borg,
3212 HTONL_FP(&peer->aorg,
3216 peer->t21_bytes = sendlen;
3217 sendpkt(&peer->srcadr, peer->dstadr, sys_ttl[peer->ttl],
3220 peer->throttle += (1 << peer->minpoll) - 2;
3223 * Capture a-posteriori timestamps
3225 get_systime(&xmt_ty);
3226 if (peer->flip != 0) { /* interleaved modes */
3228 peer->aorg = xmt_ty;
3230 peer->borg = xmt_ty;
3231 peer->flip = -peer->flip;
3233 L_SUB(&xmt_ty, &xmt_tx);
3234 LFPTOD(&xmt_ty, peer->xleave);
3235 DPRINTF(1, ("peer_xmit: at %ld %s->%s mode %d len %zu xmt %#010x.%08x\n",
3237 peer->dstadr ? stoa(&peer->dstadr->sin) : "-",
3238 stoa(&peer->srcadr), peer->hmode, sendlen,
3239 xmt_tx.l_ui, xmt_tx.l_uf));
3244 * Authentication is enabled, so the transmitted packet must be
3245 * authenticated. If autokey is enabled, fuss with the various
3246 * modes; otherwise, symmetric key cryptography is used.
3249 if (peer->flags & FLAG_SKEY) {
3250 struct exten *exten; /* extension field */
3253 * The Public Key Dance (PKD): Cryptographic credentials
3254 * are contained in extension fields, each including a
3255 * 4-octet length/code word followed by a 4-octet
3256 * association ID and optional additional data. Optional
3257 * data includes a 4-octet data length field followed by
3258 * the data itself. Request messages are sent from a
3259 * configured association; response messages can be sent
3260 * from a configured association or can take the fast
3261 * path without ever matching an association. Response
3262 * messages have the same code as the request, but have
3263 * a response bit and possibly an error bit set. In this
3264 * implementation, a message may contain no more than
3265 * one command and one or more responses.
3267 * Cryptographic session keys include both a public and
3268 * a private componet. Request and response messages
3269 * using extension fields are always sent with the
3270 * private component set to zero. Packets without
3271 * extension fields indlude the private component when
3272 * the session key is generated.
3277 * Allocate and initialize a keylist if not
3278 * already done. Then, use the list in inverse
3279 * order, discarding keys once used. Keep the
3280 * latest key around until the next one, so
3281 * clients can use client/server packets to
3282 * compute propagation delay.
3284 * Note that once a key is used from the list,
3285 * it is retained in the key cache until the
3286 * next key is used. This is to allow a client
3287 * to retrieve the encrypted session key
3288 * identifier to verify authenticity.
3290 * If for some reason a key is no longer in the
3291 * key cache, a birthday has happened or the key
3292 * has expired, so the pseudo-random sequence is
3293 * broken. In that case, purge the keylist and
3296 if (peer->keynumber == 0)
3297 make_keylist(peer, peer->dstadr);
3300 xkeyid = peer->keylist[peer->keynumber];
3301 if (authistrusted(xkeyid))
3306 peer->keyid = xkeyid;
3308 switch (peer->hmode) {
3311 * In broadcast server mode the autokey values are
3312 * required by the broadcast clients. Push them when a
3313 * new keylist is generated; otherwise, push the
3314 * association message so the client can request them at
3317 case MODE_BROADCAST:
3318 if (peer->flags & FLAG_ASSOC)
3319 exten = crypto_args(peer, CRYPTO_AUTO |
3320 CRYPTO_RESP, peer->associd, NULL);
3322 exten = crypto_args(peer, CRYPTO_ASSOC |
3323 CRYPTO_RESP, peer->associd, NULL);
3327 * In symmetric modes the parameter, certificate,
3328 * identity, cookie and autokey exchanges are
3329 * required. The leapsecond exchange is optional. But, a
3330 * peer will not believe the other peer until the other
3331 * peer has synchronized, so the certificate exchange
3332 * might loop until then. If a peer finds a broken
3333 * autokey sequence, it uses the autokey exchange to
3334 * retrieve the autokey values. In any case, if a new
3335 * keylist is generated, the autokey values are pushed.
3341 * Parameter, certificate and identity.
3344 exten = crypto_args(peer, CRYPTO_ASSOC,
3345 peer->associd, hostval.ptr);
3346 else if (!(peer->crypto & CRYPTO_FLAG_CERT))
3347 exten = crypto_args(peer, CRYPTO_CERT,
3348 peer->associd, peer->issuer);
3349 else if (!(peer->crypto & CRYPTO_FLAG_VRFY))
3350 exten = crypto_args(peer,
3351 crypto_ident(peer), peer->associd,
3355 * Cookie and autokey. We request the cookie
3356 * only when the this peer and the other peer
3357 * are synchronized. But, this peer needs the
3358 * autokey values when the cookie is zero. Any
3359 * time we regenerate the key list, we offer the
3360 * autokey values without being asked. If for
3361 * some reason either peer finds a broken
3362 * autokey sequence, the autokey exchange is
3363 * used to retrieve the autokey values.
3365 else if ( sys_leap != LEAP_NOTINSYNC
3366 && peer->leap != LEAP_NOTINSYNC
3367 && !(peer->crypto & CRYPTO_FLAG_COOK))
3368 exten = crypto_args(peer, CRYPTO_COOK,
3369 peer->associd, NULL);
3370 else if (!(peer->crypto & CRYPTO_FLAG_AUTO))
3371 exten = crypto_args(peer, CRYPTO_AUTO,
3372 peer->associd, NULL);
3373 else if ( peer->flags & FLAG_ASSOC
3374 && peer->crypto & CRYPTO_FLAG_SIGN)
3375 exten = crypto_args(peer, CRYPTO_AUTO |
3376 CRYPTO_RESP, peer->assoc, NULL);
3379 * Wait for clock sync, then sign the
3380 * certificate and retrieve the leapsecond
3383 else if (sys_leap == LEAP_NOTINSYNC)
3386 else if (!(peer->crypto & CRYPTO_FLAG_SIGN))
3387 exten = crypto_args(peer, CRYPTO_SIGN,
3388 peer->associd, hostval.ptr);
3389 else if (!(peer->crypto & CRYPTO_FLAG_LEAP))
3390 exten = crypto_args(peer, CRYPTO_LEAP,
3391 peer->associd, NULL);
3395 * In client mode the parameter, certificate, identity,
3396 * cookie and sign exchanges are required. The
3397 * leapsecond exchange is optional. If broadcast client
3398 * mode the same exchanges are required, except that the
3399 * autokey exchange is substitutes for the cookie
3400 * exchange, since the cookie is always zero. If the
3401 * broadcast client finds a broken autokey sequence, it
3402 * uses the autokey exchange to retrieve the autokey
3408 * Parameter, certificate and identity.
3411 exten = crypto_args(peer, CRYPTO_ASSOC,
3412 peer->associd, hostval.ptr);
3413 else if (!(peer->crypto & CRYPTO_FLAG_CERT))
3414 exten = crypto_args(peer, CRYPTO_CERT,
3415 peer->associd, peer->issuer);
3416 else if (!(peer->crypto & CRYPTO_FLAG_VRFY))
3417 exten = crypto_args(peer,
3418 crypto_ident(peer), peer->associd,
3422 * Cookie and autokey. These are requests, but
3423 * we use the peer association ID with autokey
3424 * rather than our own.
3426 else if (!(peer->crypto & CRYPTO_FLAG_COOK))
3427 exten = crypto_args(peer, CRYPTO_COOK,
3428 peer->associd, NULL);
3429 else if (!(peer->crypto & CRYPTO_FLAG_AUTO))
3430 exten = crypto_args(peer, CRYPTO_AUTO,
3434 * Wait for clock sync, then sign the
3435 * certificate and retrieve the leapsecond
3438 else if (sys_leap == LEAP_NOTINSYNC)
3441 else if (!(peer->crypto & CRYPTO_FLAG_SIGN))
3442 exten = crypto_args(peer, CRYPTO_SIGN,
3443 peer->associd, hostval.ptr);
3444 else if (!(peer->crypto & CRYPTO_FLAG_LEAP))
3445 exten = crypto_args(peer, CRYPTO_LEAP,
3446 peer->associd, NULL);
3451 * Add a queued extension field if present. This is
3452 * always a request message, so the reply ID is already
3453 * in the message. If an error occurs, the error bit is
3454 * lit in the response.
3456 if (peer->cmmd != NULL) {
3459 temp32 = CRYPTO_RESP;
3460 peer->cmmd->opcode |= htonl(temp32);
3461 sendlen += crypto_xmit(peer, &xpkt, NULL,
3462 sendlen, peer->cmmd, 0);
3468 * Add an extension field created above. All but the
3469 * autokey response message are request messages.
3471 if (exten != NULL) {
3472 if (exten->opcode != 0)
3473 sendlen += crypto_xmit(peer, &xpkt,
3474 NULL, sendlen, exten, 0);
3479 * Calculate the next session key. Since extension
3480 * fields are present, the cookie value is zero.
3482 if (sendlen > (int)LEN_PKT_NOMAC) {
3483 session_key(&peer->dstadr->sin, &peer->srcadr,
3487 #endif /* AUTOKEY */
3490 * Transmit a-priori timestamps
3492 get_systime(&xmt_tx);
3493 if (peer->flip == 0) { /* basic mode */
3494 peer->aorg = xmt_tx;
3495 HTONL_FP(&xmt_tx, &xpkt.xmt);
3496 } else { /* interleaved modes */
3497 if (peer->hmode == MODE_BROADCAST) { /* bcst */
3498 HTONL_FP(&xmt_tx, &xpkt.xmt);
3500 HTONL_FP(&peer->borg, &xpkt.org);
3502 HTONL_FP(&peer->aorg, &xpkt.org);
3503 } else { /* symmetric */
3505 HTONL_FP(&peer->borg, &xpkt.xmt);
3507 HTONL_FP(&peer->aorg, &xpkt.xmt);
3510 xkeyid = peer->keyid;
3511 authlen = authencrypt(xkeyid, (u_int32 *)&xpkt, sendlen);
3513 report_event(PEVNT_AUTH, peer, "no key");
3514 peer->flash |= TEST5; /* auth error */
3520 if (xkeyid > NTP_MAXKEY)
3521 authtrust(xkeyid, 0);
3522 #endif /* AUTOKEY */
3523 if (sendlen > sizeof(xpkt)) {
3524 msyslog(LOG_ERR, "peer_xmit: buffer overflow %zu", sendlen);
3527 peer->t21_bytes = sendlen;
3528 sendpkt(&peer->srcadr, peer->dstadr, sys_ttl[peer->ttl], &xpkt,
3531 peer->throttle += (1 << peer->minpoll) - 2;
3534 * Capture a-posteriori timestamps
3536 get_systime(&xmt_ty);
3537 if (peer->flip != 0) { /* interleaved modes */
3539 peer->aorg = xmt_ty;
3541 peer->borg = xmt_ty;
3542 peer->flip = -peer->flip;
3544 L_SUB(&xmt_ty, &xmt_tx);
3545 LFPTOD(&xmt_ty, peer->xleave);
3547 DPRINTF(1, ("peer_xmit: at %ld %s->%s mode %d keyid %08x len %zu index %d\n",
3548 current_time, latoa(peer->dstadr),
3549 ntoa(&peer->srcadr), peer->hmode, xkeyid, sendlen,
3551 #else /* !AUTOKEY follows */
3552 DPRINTF(1, ("peer_xmit: at %ld %s->%s mode %d keyid %08x len %d\n",
3553 current_time, peer->dstadr ?
3554 ntoa(&peer->dstadr->sin) : "-",
3555 ntoa(&peer->srcadr), peer->hmode, xkeyid, sendlen));
3556 #endif /* !AUTOKEY */
3565 leap_smear_add_offs(
3571 L_ADD(t, &leap_smear.offset);
3576 #endif /* LEAP_SMEAR */
3580 * fast_xmit - Send packet for nonpersistent association. Note that
3581 * neither the source or destination can be a broadcast address.
3585 struct recvbuf *rbufp, /* receive packet pointer */
3586 int xmode, /* receive mode */
3587 keyid_t xkeyid, /* transmit key ID */
3588 int flags /* restrict mask */
3591 struct pkt xpkt; /* transmit packet structure */
3592 struct pkt *rpkt; /* receive packet structure */
3593 l_fp xmt_tx, xmt_ty;
3600 * Initialize transmit packet header fields from the receive
3601 * buffer provided. We leave the fields intact as received, but
3602 * set the peer poll at the maximum of the receive peer poll and
3603 * the system minimum poll (ntp_minpoll). This is for KoD rate
3604 * control and not strictly specification compliant, but doesn't
3607 * If the gazinta was from a multicast address, the gazoutta
3608 * must go out another way.
3610 rpkt = &rbufp->recv_pkt;
3611 if (rbufp->dstadr->flags & INT_MCASTOPEN)
3612 rbufp->dstadr = findinterface(&rbufp->recv_srcadr);
3615 * If this is a kiss-o'-death (KoD) packet, show leap
3616 * unsynchronized, stratum zero, reference ID the four-character
3617 * kiss code and system root delay. Note we don't reveal the
3618 * local time, so these packets can't be used for
3621 if (flags & RES_KOD) {
3623 xpkt.li_vn_mode = PKT_LI_VN_MODE(LEAP_NOTINSYNC,
3624 PKT_VERSION(rpkt->li_vn_mode), xmode);
3625 xpkt.stratum = STRATUM_PKT_UNSPEC;
3626 xpkt.ppoll = max(rpkt->ppoll, ntp_minpoll);
3627 xpkt.precision = rpkt->precision;
3628 memcpy(&xpkt.refid, "RATE", 4);
3629 xpkt.rootdelay = rpkt->rootdelay;
3630 xpkt.rootdisp = rpkt->rootdisp;
3631 xpkt.reftime = rpkt->reftime;
3632 xpkt.org = rpkt->xmt;
3633 xpkt.rec = rpkt->xmt;
3634 xpkt.xmt = rpkt->xmt;
3637 * This is a normal packet. Use the system variables.
3642 * Make copies of the variables which can be affected by smearing.
3645 l_fp this_recv_time;
3649 * If we are inside the leap smear interval we add the current smear offset to
3650 * the packet receive time, to the packet transmit time, and eventually to the
3651 * reftime to make sure the reftime isn't later than the transmit/receive times.
3653 xpkt.li_vn_mode = PKT_LI_VN_MODE(xmt_leap,
3654 PKT_VERSION(rpkt->li_vn_mode), xmode);
3656 xpkt.stratum = STRATUM_TO_PKT(sys_stratum);
3657 xpkt.ppoll = max(rpkt->ppoll, ntp_minpoll);
3658 xpkt.precision = sys_precision;
3659 xpkt.refid = sys_refid;
3660 xpkt.rootdelay = HTONS_FP(DTOFP(sys_rootdelay));
3661 xpkt.rootdisp = HTONS_FP(DTOUFP(sys_rootdisp));
3664 this_ref_time = sys_reftime;
3665 if (leap_smear.in_progress) {
3666 leap_smear_add_offs(&this_ref_time, NULL);
3667 xpkt.refid = convertLFPToRefID(leap_smear.offset);
3668 DPRINTF(2, ("fast_xmit: leap_smear.in_progress: refid %8x, smear %s\n",
3670 lfptoa(&leap_smear.offset, 8)
3673 HTONL_FP(&this_ref_time, &xpkt.reftime);
3675 HTONL_FP(&sys_reftime, &xpkt.reftime);
3678 xpkt.org = rpkt->xmt;
3681 this_recv_time = rbufp->recv_time;
3682 if (leap_smear.in_progress)
3683 leap_smear_add_offs(&this_recv_time, NULL);
3684 HTONL_FP(&this_recv_time, &xpkt.rec);
3686 HTONL_FP(&rbufp->recv_time, &xpkt.rec);
3689 get_systime(&xmt_tx);
3691 if (leap_smear.in_progress)
3692 leap_smear_add_offs(&xmt_tx, &this_recv_time);
3694 HTONL_FP(&xmt_tx, &xpkt.xmt);
3697 #ifdef HAVE_NTP_SIGND
3698 if (flags & RES_MSSNTP) {
3699 send_via_ntp_signd(rbufp, xmode, xkeyid, flags, &xpkt);
3702 #endif /* HAVE_NTP_SIGND */
3705 * If the received packet contains a MAC, the transmitted packet
3706 * is authenticated and contains a MAC. If not, the transmitted
3707 * packet is not authenticated.
3709 sendlen = LEN_PKT_NOMAC;
3710 if (rbufp->recv_length == sendlen) {
3711 sendpkt(&rbufp->recv_srcadr, rbufp->dstadr, 0, &xpkt,
3713 DPRINTF(1, ("fast_xmit: at %ld %s->%s mode %d len %lu\n",
3714 current_time, stoa(&rbufp->dstadr->sin),
3715 stoa(&rbufp->recv_srcadr), xmode,
3721 * The received packet contains a MAC, so the transmitted packet
3722 * must be authenticated. For symmetric key cryptography, use
3723 * the predefined and trusted symmetric keys to generate the
3724 * cryptosum. For autokey cryptography, use the server private
3725 * value to generate the cookie, which is unique for every
3726 * source-destination-key ID combination.
3729 if (xkeyid > NTP_MAXKEY) {
3733 * The only way to get here is a reply to a legitimate
3734 * client request message, so the mode must be
3735 * MODE_SERVER. If an extension field is present, there
3736 * can be only one and that must be a command. Do what
3737 * needs, but with private value of zero so the poor
3738 * jerk can decode it. If no extension field is present,
3739 * use the cookie to generate the session key.
3741 cookie = session_key(&rbufp->recv_srcadr,
3742 &rbufp->dstadr->sin, 0, sys_private, 0);
3743 if ((size_t)rbufp->recv_length > sendlen + MAX_MAC_LEN) {
3744 session_key(&rbufp->dstadr->sin,
3745 &rbufp->recv_srcadr, xkeyid, 0, 2);
3746 temp32 = CRYPTO_RESP;
3747 rpkt->exten[0] |= htonl(temp32);
3748 sendlen += crypto_xmit(NULL, &xpkt, rbufp,
3749 sendlen, (struct exten *)rpkt->exten,
3752 session_key(&rbufp->dstadr->sin,
3753 &rbufp->recv_srcadr, xkeyid, cookie, 2);
3756 #endif /* AUTOKEY */
3757 get_systime(&xmt_tx);
3758 sendlen += authencrypt(xkeyid, (u_int32 *)&xpkt, sendlen);
3760 if (xkeyid > NTP_MAXKEY)
3761 authtrust(xkeyid, 0);
3762 #endif /* AUTOKEY */
3763 sendpkt(&rbufp->recv_srcadr, rbufp->dstadr, 0, &xpkt, sendlen);
3764 get_systime(&xmt_ty);
3765 L_SUB(&xmt_ty, &xmt_tx);
3766 sys_authdelay = xmt_ty;
3767 DPRINTF(1, ("fast_xmit: at %ld %s->%s mode %d keyid %08x len %lu\n",
3768 current_time, ntoa(&rbufp->dstadr->sin),
3769 ntoa(&rbufp->recv_srcadr), xmode, xkeyid,
3775 * pool_xmit - resolve hostname or send unicast solicitation for pool.
3779 struct peer *pool /* pool solicitor association */
3783 struct pkt xpkt; /* transmit packet structure */
3784 struct addrinfo hints;
3786 struct interface * lcladr;
3787 sockaddr_u * rmtadr;
3792 if (NULL == pool->ai) {
3793 if (pool->addrs != NULL) {
3794 /* free() is used with copy_addrinfo_list() */
3799 hints.ai_family = AF(&pool->srcadr);
3800 hints.ai_socktype = SOCK_DGRAM;
3801 hints.ai_protocol = IPPROTO_UDP;
3802 /* ignore getaddrinfo_sometime() errors, we will retry */
3803 rc = getaddrinfo_sometime(
3808 &pool_name_resolved,
3809 (void *)(intptr_t)pool->associd);
3811 DPRINTF(1, ("pool DNS lookup %s started\n",
3815 "unable to start pool DNS %s: %m",
3821 /* copy_addrinfo_list ai_addr points to a sockaddr_u */
3822 rmtadr = (sockaddr_u *)(void *)pool->ai->ai_addr;
3823 pool->ai = pool->ai->ai_next;
3824 p = findexistingpeer(rmtadr, NULL, NULL, MODE_CLIENT, 0);
3825 } while (p != NULL && pool->ai != NULL);
3827 return; /* out of addresses, re-query DNS next poll */
3828 restrict_mask = restrictions(rmtadr);
3829 if (RES_FLAGS & restrict_mask)
3830 restrict_source(rmtadr, 0,
3831 current_time + POOL_SOLICIT_WINDOW + 1);
3832 lcladr = findinterface(rmtadr);
3833 memset(&xpkt, 0, sizeof(xpkt));
3834 xpkt.li_vn_mode = PKT_LI_VN_MODE(sys_leap, pool->version,
3836 xpkt.stratum = STRATUM_TO_PKT(sys_stratum);
3837 xpkt.ppoll = pool->hpoll;
3838 xpkt.precision = sys_precision;
3839 xpkt.refid = sys_refid;
3840 xpkt.rootdelay = HTONS_FP(DTOFP(sys_rootdelay));
3841 xpkt.rootdisp = HTONS_FP(DTOUFP(sys_rootdisp));
3842 HTONL_FP(&sys_reftime, &xpkt.reftime);
3843 get_systime(&xmt_tx);
3844 pool->aorg = xmt_tx;
3845 HTONL_FP(&xmt_tx, &xpkt.xmt);
3846 sendpkt(rmtadr, lcladr, sys_ttl[pool->ttl], &xpkt,
3849 pool->throttle += (1 << pool->minpoll) - 2;
3850 DPRINTF(1, ("pool_xmit: at %ld %s->%s pool\n",
3851 current_time, latoa(lcladr), stoa(rmtadr)));
3852 msyslog(LOG_INFO, "Soliciting pool server %s", stoa(rmtadr));
3859 * group_test - test if this is the same group
3861 * host assoc return action
3862 * none none 0 mobilize *
3863 * none group 0 mobilize *
3864 * group none 0 mobilize *
3865 * group group 1 mobilize
3866 * group different 1 ignore
3867 * * ignore if notrust
3878 if (strcmp(grp, sys_groupname) == 0)
3884 if (strcmp(grp, ident) == 0)
3889 #endif /* AUTOKEY */
3898 const char * service,
3899 const struct addrinfo * hints,
3900 const struct addrinfo * res
3903 struct peer * pool; /* pool solicitor association */
3908 "error resolving pool %s: %s (%d)",
3909 name, gai_strerror(rescode), rescode);
3913 assoc = (associd_t)(intptr_t)context;
3914 pool = findpeerbyassoc(assoc);
3917 "Could not find assoc %u for pool DNS %s",
3921 DPRINTF(1, ("pool DNS %s completed\n", name));
3922 pool->addrs = copy_addrinfo_list(res);
3923 pool->ai = pool->addrs;
3932 * key_expire - purge the key list
3936 struct peer *peer /* peer structure pointer */
3941 if (peer->keylist != NULL) {
3942 for (i = 0; i <= peer->keynumber; i++)
3943 authtrust(peer->keylist[i], 0);
3944 free(peer->keylist);
3945 peer->keylist = NULL;
3947 value_free(&peer->sndval);
3948 peer->keynumber = 0;
3949 peer->flags &= ~FLAG_ASSOC;
3950 DPRINTF(1, ("key_expire: at %lu associd %d\n", current_time,
3953 #endif /* AUTOKEY */
3957 * local_refid(peer) - check peer refid to avoid selecting peers
3958 * currently synced to this ntpd.
3967 if (p->dstadr != NULL && !(INT_MCASTIF & p->dstadr->flags))
3968 unicast_ep = p->dstadr;
3970 unicast_ep = findinterface(&p->srcadr);
3972 if (unicast_ep != NULL && p->refid == unicast_ep->addr_refid)
3980 * Determine if the peer is unfit for synchronization
3982 * A peer is unfit for synchronization if
3983 * > TEST10 bad leap or stratum below floor or at or above ceiling
3984 * > TEST11 root distance exceeded for remote peer
3985 * > TEST12 a direct or indirect synchronization loop would form
3986 * > TEST13 unreachable or noselect
3988 int /* FALSE if fit, TRUE if unfit */
3990 struct peer *peer /* peer structure pointer */
3996 * A stratum error occurs if (1) the server has never been
3997 * synchronized, (2) the server stratum is below the floor or
3998 * greater than or equal to the ceiling.
4000 if ( peer->leap == LEAP_NOTINSYNC
4001 || peer->stratum < sys_floor
4002 || peer->stratum >= sys_ceiling)
4003 rval |= TEST10; /* bad synch or stratum */
4006 * A distance error for a remote peer occurs if the root
4007 * distance is greater than or equal to the distance threshold
4008 * plus the increment due to one host poll interval.
4010 if ( !(peer->flags & FLAG_REFCLOCK)
4011 && root_distance(peer) >= sys_maxdist
4012 + clock_phi * ULOGTOD(peer->hpoll))
4013 rval |= TEST11; /* distance exceeded */
4016 * A loop error occurs if the remote peer is synchronized to the
4017 * local peer or if the remote peer is synchronized to the same
4018 * server as the local peer but only if the remote peer is
4019 * neither a reference clock nor an orphan.
4021 if (peer->stratum > 1 && local_refid(peer))
4022 rval |= TEST12; /* synchronization loop */
4025 * An unreachable error occurs if the server is unreachable or
4026 * the noselect bit is set.
4028 if (!peer->reach || (peer->flags & FLAG_NOSELECT))
4029 rval |= TEST13; /* unreachable */
4031 peer->flash &= ~PEER_TEST_MASK;
4032 peer->flash |= rval;
4038 * Find the precision of this particular machine
4040 #define MINSTEP 20e-9 /* minimum clock increment (s) */
4041 #define MAXSTEP 1 /* maximum clock increment (s) */
4042 #define MINCHANGES 12 /* minimum number of step samples */
4043 #define MAXLOOPS ((int)(1. / MINSTEP)) /* avoid infinite loop */
4046 * This routine measures the system precision defined as the minimum of
4047 * a sequence of differences between successive readings of the system
4048 * clock. However, if a difference is less than MINSTEP, the clock has
4049 * been read more than once during a clock tick and the difference is
4050 * ignored. We set MINSTEP greater than zero in case something happens
4051 * like a cache miss, and to tolerate underlying system clocks which
4052 * ensure each reading is strictly greater than prior readings while
4053 * using an underlying stepping (not interpolated) clock.
4055 * sys_tick and sys_precision represent the time to read the clock for
4056 * systems with high-precision clocks, and the tick interval or step
4057 * size for lower-precision stepping clocks.
4059 * This routine also measures the time to read the clock on stepping
4060 * system clocks by counting the number of readings between changes of
4061 * the underlying clock. With either type of clock, the minimum time
4062 * to read the clock is saved as sys_fuzz, and used to ensure the
4063 * get_systime() readings always increase and are fuzzed below sys_fuzz.
4066 measure_precision(void)
4069 * With sys_fuzz set to zero, get_systime() fuzzing of low bits
4070 * is effectively disabled. trunc_os_clock is FALSE to disable
4071 * get_ostime() simulation of a low-precision system clock.
4074 trunc_os_clock = FALSE;
4075 measured_tick = measure_tick_fuzz();
4076 set_sys_tick_precision(measured_tick);
4077 msyslog(LOG_INFO, "proto: precision = %.3f usec (%d)",
4078 sys_tick * 1e6, sys_precision);
4079 if (sys_fuzz < sys_tick) {
4080 msyslog(LOG_NOTICE, "proto: fuzz beneath %.3f usec",
4087 * measure_tick_fuzz()
4089 * measures the minimum time to read the clock (stored in sys_fuzz)
4090 * and returns the tick, the larger of the minimum increment observed
4091 * between successive clock readings and the time to read the clock.
4094 measure_tick_fuzz(void)
4096 l_fp minstep; /* MINSTEP as l_fp */
4097 l_fp val; /* current seconds fraction */
4098 l_fp last; /* last seconds fraction */
4099 l_fp ldiff; /* val - last */
4100 double tick; /* computed tick value */
4105 int i; /* log2 precision */
4111 DTOLFP(MINSTEP, &minstep);
4113 for (i = 0; i < MAXLOOPS && changes < MINCHANGES; i++) {
4116 L_SUB(&ldiff, &last);
4118 if (L_ISGT(&ldiff, &minstep)) {
4119 max_repeats = max(repeats, max_repeats);
4122 LFPTOD(&ldiff, diff);
4123 tick = min(diff, tick);
4128 if (changes < MINCHANGES) {
4129 msyslog(LOG_ERR, "Fatal error: precision could not be measured (MINSTEP too large?)");
4133 if (0 == max_repeats) {
4136 set_sys_fuzz(tick / max_repeats);
4144 set_sys_tick_precision(
4152 "unsupported tick %.3f > 1s ignored", tick);
4155 if (tick < measured_tick) {
4157 "proto: tick %.3f less than measured tick %.3f, ignored",
4158 tick, measured_tick);
4160 } else if (tick > measured_tick) {
4161 trunc_os_clock = TRUE;
4163 "proto: truncating system clock to multiples of %.9f",
4169 * Find the nearest power of two.
4171 for (i = 0; tick <= 1; i--)
4173 if (tick - 1 > 1 - tick / 2)
4176 sys_precision = (s_char)i;
4181 * init_proto - initialize the protocol module's data
4190 * Fill in the sys_* stuff. Default is don't listen to
4191 * broadcasting, require authentication.
4193 set_sys_leap(LEAP_NOTINSYNC);
4194 sys_stratum = STRATUM_UNSPEC;
4195 memcpy(&sys_refid, "INIT", 4);
4199 L_CLR(&sys_reftime);
4201 measure_precision();
4202 get_systime(&dummy);
4204 sys_manycastserver = 0;
4207 sys_authenticate = 1;
4208 sys_stattime = current_time;
4209 orphwait = current_time + sys_orphwait;
4211 for (i = 0; i < MAX_TTL; i++) {
4212 sys_ttl[i] = (u_char)((i * 256) / MAX_TTL);
4221 * proto_config - configure the protocol module
4232 * Figure out what he wants to change, then do it
4234 DPRINTF(2, ("proto_config: code %d value %lu dvalue %lf\n",
4235 item, value, dvalue));
4240 * enable and disable commands - arguments are Boolean.
4242 case PROTO_AUTHENTICATE: /* authentication (auth) */
4243 sys_authenticate = value;
4246 case PROTO_BROADCLIENT: /* broadcast client (bclient) */
4247 sys_bclient = (int)value;
4248 if (sys_bclient == 0)
4255 case PROTO_CAL: /* refclock calibrate (calibrate) */
4258 #endif /* REFCLOCK */
4260 case PROTO_KERNEL: /* kernel discipline (kernel) */
4264 case PROTO_MONITOR: /* monitoring (monitor) */
4270 msyslog(LOG_WARNING,
4271 "restrict: 'monitor' cannot be disabled while 'limited' is enabled");
4275 case PROTO_NTP: /* NTP discipline (ntp) */
4279 case PROTO_MODE7: /* mode7 management (ntpdc) */
4283 case PROTO_PPS: /* PPS discipline (pps) */
4284 hardpps_enable = value;
4287 case PROTO_FILEGEN: /* statistics (stats) */
4288 stats_control = value;
4292 * tos command - arguments are double, sometimes cast to int
4294 case PROTO_BEACON: /* manycast beacon (beacon) */
4295 sys_beacon = (int)dvalue;
4298 case PROTO_BROADDELAY: /* default broadcast delay (bdelay) */
4299 sys_bdelay = dvalue;
4302 case PROTO_CEILING: /* stratum ceiling (ceiling) */
4303 sys_ceiling = (int)dvalue;
4306 case PROTO_COHORT: /* cohort switch (cohort) */
4307 sys_cohort = (int)dvalue;
4310 case PROTO_FLOOR: /* stratum floor (floor) */
4311 sys_floor = (int)dvalue;
4314 case PROTO_MAXCLOCK: /* maximum candidates (maxclock) */
4315 sys_maxclock = (int)dvalue;
4318 case PROTO_MAXDIST: /* select threshold (maxdist) */
4319 sys_maxdist = dvalue;
4322 case PROTO_CALLDELAY: /* modem call delay (mdelay) */
4323 break; /* NOT USED */
4325 case PROTO_MINCLOCK: /* minimum candidates (minclock) */
4326 sys_minclock = (int)dvalue;
4329 case PROTO_MINDISP: /* minimum distance (mindist) */
4330 sys_mindisp = dvalue;
4333 case PROTO_MINSANE: /* minimum survivors (minsane) */
4334 sys_minsane = (int)dvalue;
4337 case PROTO_ORPHAN: /* orphan stratum (orphan) */
4338 sys_orphan = (int)dvalue;
4341 case PROTO_ORPHWAIT: /* orphan wait (orphwait) */
4342 orphwait -= sys_orphwait;
4343 sys_orphwait = (int)dvalue;
4344 orphwait += sys_orphwait;
4348 * Miscellaneous commands
4350 case PROTO_MULTICAST_ADD: /* add group address */
4352 io_multicast_add(svalue);
4356 case PROTO_MULTICAST_DEL: /* delete group address */
4358 io_multicast_del(svalue);
4363 "proto: unsupported option %d", item);
4369 * proto_clr_stats - clear protocol stat counters
4372 proto_clr_stats(void)
4374 sys_stattime = current_time;
4383 sys_limitrejected = 0;
projects / FreeBSD / releng / 9.3.git / blob