From 8a8eed52b94c1c59ad62c02c7e70ba4e63cc78c7 Mon Sep 17 00:00:00 2001 From: roberto Date: Wed, 29 Aug 2001 15:15:59 +0000 Subject: Merge after 4.1.0 import. --- contrib/ntp/ntpd/ntp_proto.c | 2559 ++++++++++++++++++++++++++---------------- 1 file changed, 1573 insertions(+), 986 deletions(-) (limited to 'contrib/ntp') diff --git a/contrib/ntp/ntpd/ntp_proto.c b/contrib/ntp/ntpd/ntp_proto.c index fd59a6b..2374afa 100644 --- a/contrib/ntp/ntpd/ntp_proto.c +++ b/contrib/ntp/ntpd/ntp_proto.c @@ -7,15 +7,14 @@ #include #endif -#include -#include -#include - #include "ntpd.h" #include "ntp_stdlib.h" #include "ntp_unixtime.h" #include "ntp_control.h" #include "ntp_string.h" +#include "ntp_crypto.h" + +#include #if defined(VMS) && defined(VMS_LOCALUNIT) /*wjm*/ #include "ntp_refclock.h" @@ -26,19 +25,22 @@ #endif /* - * System variables are declared here. See Section 3.2 of the + * System variables are declared here. See Section 3.2 of the * specification. */ u_char sys_leap; /* system leap indicator */ u_char sys_stratum; /* stratum of system */ s_char sys_precision; /* local clock precision */ -double sys_rootdelay; /* distance to current sync source */ -double sys_rootdispersion; /* dispersion of system clock */ +double sys_rootdelay; /* roundtrip delay to primary source */ +double sys_rootdispersion; /* dispersion to primary source */ u_int32 sys_refid; /* reference source for local clock */ static double sys_offset; /* current local clock offset */ l_fp sys_reftime; /* time we were last updated */ struct peer *sys_peer; /* our current peer */ +struct peer *sys_prefer; /* our cherished peer */ +#ifdef AUTOKEY u_long sys_automax; /* maximum session key lifetime */ +#endif /* AUTOKEY */ /* * Nonspecified system state variables. @@ -49,10 +51,15 @@ int sys_authenticate; /* requre authentication for config */ l_fp sys_authdelay; /* authentication delay */ static u_long sys_authdly[2]; /* authentication delay shift reg */ static u_char leap_consensus; /* consensus of survivor leap bits */ -static double sys_maxd; /* select error (squares) */ -static double sys_epsil; /* system error (squares) */ -u_long sys_private; /* private value for session seed */ -int sys_manycastserver; /* 1 => respond to manycast client pkts */ +static double sys_selerr; /* select error (squares) */ +static double sys_syserr; /* system error (squares) */ +keyid_t sys_private; /* private value for session seed */ +int sys_manycastserver; /* respond to manycast client pkts */ +u_int sys_survivors; /* truest of the truechimers */ +int peer_ntpdate; /* active peers in ntpdate mode */ +#ifdef AUTOKEY +char *sys_hostname; /* gethostname() name */ +#endif /* AUTOKEY */ /* * Statistics counters @@ -70,12 +77,10 @@ u_long sys_limitrejected; /* pkts rejected due to client count per net */ static double root_distance P((struct peer *)); static double clock_combine P((struct peer **, int)); static void peer_xmit P((struct peer *)); -static void fast_xmit P((struct recvbuf *, int, u_long)); +static void fast_xmit P((struct recvbuf *, int, keyid_t, int)); static void clock_update P((void)); int default_get_precision P((void)); -#ifdef MD5 -static void make_keylist P((struct peer *)); -#endif /* MD5 */ + /* * transmit - Transmit Procedure. See Section 3.4.2 of the @@ -93,116 +98,173 @@ transmit( u_char oreach; /* - * Determine reachability and diddle things if we - * haven't heard from the host for a while. If the peer - * is not configured and not likely to stay around, - * we exhaust it. + * The polling state machine. There are two kinds of + * machines, those that never expect a reply (broadcast + * and manycast server modes) and those that do (all + * other modes). The dance is intricate... */ + if (peer->cast_flags & (MDF_BCAST | MDF_MCAST)) { + + /* + * In broadcast mode the poll interval is fixed + * at minpoll and the ttl at ttlmax. + */ + hpoll = peer->minpoll; + peer->ttl = peer->ttlmax; +#ifdef AUTOKEY + } else if (peer->cast_flags & MDF_ACAST) { + + /* + * In manycast mode we start with the minpoll + * interval and ttl. However, the actual poll + * interval is eight times the nominal poll + * interval shown here. If fewer than three + * servers are found, the ttl is increased by + * one and we try again. If this continues to + * the max ttl, the poll interval is bumped by + * one and we try again. If at least three + * servers are found, the poll interval + * increases with the system poll interval to + * the max and we continue indefinately. + * However, about once per day when the + * agreement parameters are refreshed, the + * manycast clients are reset and we start from + * the beginning. This is to catch and clamp the + * ttl to the lowest practical value and avoid + * knocking on spurious doors. + */ + if (sys_survivors < NTP_MINCLOCK && peer->ttl < + peer->ttlmax) + peer->ttl++; + hpoll = sys_poll; +#endif /* AUTOKEY */ + } else { + + /* + * For associations expecting a reply, the + * watchdog counter is bumped by one if the peer + * has not been heard since the previous poll. + * If the counter reaches the max, the peer is + * demobilized if not configured and just + * cleared if it is, but in this case the poll + * interval is bumped by one. + */ + if (peer->unreach < NTP_UNREACH) { + peer->unreach++; + } else if (!(peer->flags & FLAG_CONFIG)) { + unpeer(peer); + clock_select(); + return; + + } else { + peer_clear(peer); + hpoll++; + } + } oreach = peer->reach; - if (oreach & 0x01) - peer->valid++; - if (oreach & 0x80) - peer->valid--; - if (!(peer->flags & FLAG_CONFIG) && peer->valid > - NTP_SHIFT / 2 && (peer->reach & 0x80) && - peer->status < CTL_PST_SEL_SYNCCAND) - peer->reach = 0; peer->reach <<= 1; if (peer->reach == 0) { /* - * If this is an uncofigured association and - * has become unreachable, demobilize it. + * If this association has become unreachable, + * clear it and raise a trap. */ if (oreach != 0) { report_event(EVNT_UNREACH, peer); peer->timereachable = current_time; - peer_clear(peer); if (!(peer->flags & FLAG_CONFIG)) { unpeer(peer); + clock_select(); return; + } else { + peer_clear(peer); + hpoll = peer->minpoll; } } - - /* - * We would like to respond quickly when the - * peer comes back to life. If the probes since - * becoming unreachable are less than - * NTP_UNREACH, clamp the poll interval to the - * minimum. In order to minimize the network - * traffic, the interval gradually ramps up the - * the maximum after that. - */ - peer->ppoll = peer->maxpoll; - if (peer->unreach < NTP_UNREACH) { - if (peer->hmode == MODE_CLIENT) - peer->unreach++; - hpoll = peer->minpoll; - } else { - hpoll++; - } - if (peer->flags & FLAG_BURST) - peer->burst = 2; - + if (peer->flags & FLAG_IBURST) + peer->burst = NTP_SHIFT; } else { /* - * Here the peer is reachable. If there is no - * system peer or if the stratum of the system - * peer is greater than this peer, clamp the - * poll interval to the minimum. If less than - * two samples are in the reachability register, - * reduce the interval; if more than six samples - * are in the register, increase the interval. + * Here the peer is reachable. If it has not + * been heard for three consecutive polls, stuff + * the clock filter. Next, determine the poll + * interval. If the peer is a synchronization + * candidate, use the system poll interval. If + * the peer is not sane, increase it by one. If + * the number of valid updates is not greater + * than half the register size, clamp it to the + * minimum. This is to quickly recover the time + * variables when a noisy peer shows life. */ - peer->unreach = 0; - if (sys_peer == 0) - hpoll = peer->minpoll; - else if (sys_peer->stratum > peer->stratum) - hpoll = peer->minpoll; - if ((peer->reach & 0x03) == 0) { + if (!(peer->reach & 0x07)) { clock_filter(peer, 0., 0., MAXDISPERSE); clock_select(); } - if (peer->valid <= 2) - hpoll--; - else if (peer->valid >= NTP_SHIFT - 2) + if ((peer->stratum > 1 && peer->refid == + peer->dstadr->sin.sin_addr.s_addr) || + peer->stratum >= STRATUM_UNSPEC) hpoll++; + else + hpoll = sys_poll; if (peer->flags & FLAG_BURST) peer->burst = NTP_SHIFT; } } else { peer->burst--; if (peer->burst == 0) { - if (peer->flags & FLAG_MCAST2) { - peer->flags &= ~FLAG_BURST; + + /* + * If a broadcast client at this point, the + * burst has concluded, so we switch to client + * mode and purge the keylist, since no further + * transmissions will be made. + */ + if (peer->cast_flags & MDF_BCLNT) { peer->hmode = MODE_BCLIENT; +#ifdef AUTOKEY + key_expire(peer); +#endif /* AUTOKEY */ } - clock_select(); poll_update(peer, hpoll); + clock_select(); + + /* + * If ntpdate mode and the clock has not been + * set and all peers have completed the burst, + * we declare a successful failure. + */ + if (mode_ntpdate) { + peer_ntpdate--; + if (peer_ntpdate > 0) + return; + NLOG(NLOG_SYNCEVENT | NLOG_SYSEVENT) + msyslog(LOG_NOTICE, + "no reply; clock not set"); + printf( + "ntpd: no reply; clock not set\n"); + exit(0); + } return; + } } + peer->outdate = current_time; + poll_update(peer, hpoll); /* - * We need to be very careful about honking uncivilized time. If - * not operating in broadcast mode, honk in all except broadcast - * client mode. If operating in broadcast mode and synchronized - * to a real source, honk except when the peer is the local- - * clock driver and the prefer flag is not set. In other words, - * in broadcast mode we never honk unless known to be - * synchronized to real time. + * We need to be very careful about honking uncivilized time. + * Never transmit if in broadcast client mode or access denied. + * If in broadcast mode, transmit only if synchronized to a + * valid source. */ - if (peer->hmode != MODE_BROADCAST) { - if (peer->hmode != MODE_BCLIENT) - peer_xmit(peer); - } else if (sys_peer != 0 && sys_leap != LEAP_NOTINSYNC) { - if (!(sys_peer->refclktype == REFCLK_LOCALCLOCK && - !(sys_peer->flags & FLAG_PREFER))) - peer_xmit(peer); + if (peer->hmode == MODE_BCLIENT || peer->flash & TEST4) { + return; + } else if (peer->hmode == MODE_BROADCAST) { + if (sys_peer == NULL) + return; } - peer->outdate = current_time; - poll_update(peer, hpoll); + peer_xmit(peer); } /* @@ -218,482 +280,552 @@ receive( int hismode; int oflags; int restrict_mask; - int has_mac; /* has MAC field */ - int authlen; /* length of MAC field */ + int has_mac; /* length of MAC field */ + int authlen; /* offset of MAC field */ int is_authentic; /* cryptosum ok */ - int is_mystic; /* session key exists */ - int is_error; /* parse error */ -/* u_long pkeyid; */ - u_long skeyid, tkeyid; + keyid_t skeyid; /* cryptographic keys */ + struct sockaddr_in *dstadr_sin; /* active runway */ +#ifdef AUTOKEY + keyid_t pkeyid, tkeyid; /* cryptographic keys */ +#endif /* AUTOKEY */ struct peer *peer2; int retcode = AM_NOMATCH; /* - * Monitor the packet and get restrictions + * Monitor the packet and get restrictions. Note that the packet + * length for control and private mode packets must be checked + * by the service routines. Note that no statistics counters are + * recorded for restrict violations, since these counters are in + * the restriction routine. Note the careful distinctions here + * between a packet with a format error and a packet that is + * simply discarded without prejudice. Some restrictions have to + * be handled later in order to generate a kiss-of-death packet. */ ntp_monitor(rbufp); restrict_mask = restrictions(&rbufp->recv_srcadr); #ifdef DEBUG - if (debug > 1) - printf("receive: from %s restrict %02x\n", + if (debug > 2) + printf("receive: at %ld %s<-%s restrict %02x\n", + current_time, ntoa(&rbufp->dstadr->sin), ntoa(&rbufp->recv_srcadr), restrict_mask); #endif if (restrict_mask & RES_IGNORE) - return; - - /* - * Discard packets with invalid version number. - */ + return; /* no anything */ + if (!(SRCPORT(&rbufp->recv_srcadr) == NTP_PORT || + SRCPORT(&rbufp->recv_srcadr) >= IPPORT_RESERVED)) { + sys_badlength++; + return; /* invalid port */ + } pkt = &rbufp->recv_pkt; - if (PKT_VERSION(pkt->li_vn_mode) >= NTP_VERSION) - sys_newversionpkt++; - else if (PKT_VERSION(pkt->li_vn_mode) >= NTP_OLDVERSION) - sys_oldversionpkt++; - else { + if (PKT_VERSION(pkt->li_vn_mode) == NTP_VERSION) { + sys_newversionpkt++; /* new version */ + } else if (!(restrict_mask & RES_VERSION) && + PKT_VERSION(pkt->li_vn_mode) >= NTP_OLDVERSION) { + sys_oldversionpkt++; /* old version */ + } else { sys_unknownversion++; - return; + return; /* invalid version */ } - - /* - * Restrict control/private mode packets. Note that packet - * length has to be checked in the control/private mode protocol - * module. - */ if (PKT_MODE(pkt->li_vn_mode) == MODE_PRIVATE) { if (restrict_mask & RES_NOQUERY) - return; + return; /* no query private */ process_private(rbufp, ((restrict_mask & RES_NOMODIFY) == 0)); return; } if (PKT_MODE(pkt->li_vn_mode) == MODE_CONTROL) { if (restrict_mask & RES_NOQUERY) - return; + return; /* no query control */ process_control(rbufp, restrict_mask); return; } + if (rbufp->recv_length < LEN_PKT_NOMAC) { + sys_badlength++; + return; /* runt packet */ + } /* - * Restrict revenue packets. - */ - if (restrict_mask & RES_DONTSERVE) - return; - - /* - * See if we only accept limited number of clients from the net - * this guy is from. Note: the flag is determined dynamically - * within restrictions() + * Validate mode. Note that NTPv1 is no longer supported. */ - if (restrict_mask & RES_LIMITED) { - sys_limitrejected++; - return; - } + hismode = (int)PKT_MODE(pkt->li_vn_mode); + if (hismode == MODE_UNSPEC) { + sys_badlength++; + return; /* invalid mode */ + } /* - * If we are not a broadcast client, ignore broadcast packets. + * Discard broadcast packets received on the wildcard interface + * or if not enabled as broadcast client. */ - if ((PKT_MODE(pkt->li_vn_mode) == MODE_BROADCAST && - !sys_bclient)) + if (PKT_MODE(pkt->li_vn_mode) == MODE_BROADCAST && + (rbufp->dstadr == any_interface || !sys_bclient)) return; /* - * This is really awful ugly. We figure out whether an extension - * field is present and then measure the MAC size. If the number - * of words following the packet header is less than or equal to - * 5, no extension field is present and these words constitute - * the MAC. If the number of words is greater than 5, an - * extension field is present and the first word contains the - * length of the extension field and the MAC follows that. + * Parse the extension field if present. We figure out whether + * an extension field is present by measuring the MAC size. If + * the number of words following the packet header is 0 or 1, no + * MAC is present and the packet is not authenticated. If 1, the + * packet is a reply to a previous request that failed to + * authenticate. If 3, the packet is authenticated with DES; if + * 5, the packet is authenticated with MD5. If greater than 5, + * an extension field is present. If 2 or 4, the packet is a + * runt and goes poof! with a brilliant flash. */ - has_mac = 0; -/* pkeyid = 0; */ - skeyid = tkeyid = 0; + skeyid = 0; +#ifdef AUTOKEY + pkeyid = tkeyid = 0; +#endif /* AUTOKEY */ authlen = LEN_PKT_NOMAC; - has_mac = rbufp->recv_length - authlen; - if (has_mac <= 5 * sizeof(u_int32)) { - skeyid = (u_long)ntohl(pkt->keyid1) & 0xffffffff; - } else { - authlen += (u_long)ntohl(pkt->keyid1) & 0xffffffff; - has_mac = rbufp->recv_length - authlen; - if (authlen <= 0) { + while ((has_mac = rbufp->recv_length - authlen) > 0) { + int temp; + + if (has_mac % 4 != 0 || has_mac < 0) { sys_badlength++; return; } + if (has_mac == 1 * 4 || has_mac == 3 * 4 || has_mac == + MAX_MAC_LEN) { + skeyid = ntohl(((u_int32 *)pkt)[authlen / 4]); + break; - /* - * Note that keyid3 is actually the key ident of the - * MAC itself. - */ -/* pkeyid = (u_long)ntohl(pkt->keyid2) & 0xffffffff; */ - skeyid = tkeyid = (u_long)ntohl(pkt->keyid3) & - 0xffffffff; - } - - /* - * Figure out his mode and validate it. - */ - hismode = (int)PKT_MODE(pkt->li_vn_mode); - if (PKT_VERSION(pkt->li_vn_mode) == NTP_OLDVERSION && hismode == - 0) { - /* - * Easy. If it is from the NTP port it is - * a sym act, else client. - */ - if (SRCPORT(&rbufp->recv_srcadr) == NTP_PORT) - hismode = MODE_ACTIVE; - else - hismode = MODE_CLIENT; - } else { - if (hismode != MODE_ACTIVE && hismode != MODE_PASSIVE && - hismode != MODE_SERVER && hismode != MODE_CLIENT && - hismode != MODE_BROADCAST) + } else if (has_mac > MAX_MAC_LEN) { + temp = ntohl(((u_int32 *)pkt)[authlen / 4]) & + 0xffff; + if (temp < 4 || temp % 4 != 0) { + sys_badlength++; + return; + } + authlen += temp; + } else { + sys_badlength++; return; + } } /* - * If he included a mac field, decrypt it to see if it is - * authentic. + * We have tossed out as many buggy packets as possible early in + * the game to reduce the exposure to a clogging attack. Now we + * have to burn some cycles to find the association and + * authenticate the packet if required. Note that we burn only + * MD5 or DES cycles, again to reduce exposure. There may be no + * matching association and that's okay. + * + * More on the autokey mambo. Normally the local interface is + * found when the association was mobilized with respect to a + * designated remote address. We assume packets arriving from + * the remote address arrive via this interface and the local + * address used to construct the autokey is the unicast address + * of the interface. However, if the sender is a broadcaster, + * the interface broadcast address is used instead. + * Notwithstanding this technobabble, if the sender is a + * multicaster, the broadcast address is null, so we use the + * unicast address anyway. Don't ask. */ - is_authentic = is_mystic = 0; + peer = findpeer(&rbufp->recv_srcadr, rbufp->dstadr, rbufp->fd, + hismode, &retcode); + is_authentic = 0; + dstadr_sin = &rbufp->dstadr->sin; if (has_mac == 0) { #ifdef DEBUG if (debug) - printf("receive: at %ld from %s mode %d\n", - current_time, ntoa(&rbufp->recv_srcadr), - hismode); + printf("receive: at %ld %s<-%s mode %d code %d\n", + current_time, ntoa(&rbufp->dstadr->sin), + ntoa(&rbufp->recv_srcadr), hismode, retcode); #endif } else { - is_mystic = authistrusted(skeyid); -#ifdef MD5 - if (skeyid > NTP_MAXKEY && !is_mystic) { - +#ifdef AUTOKEY + /* + * For autokey modes, generate the session key + * and install in the key cache. Use the socket + * broadcast or unicast address as appropriate. + */ + if (skeyid > NTP_MAXKEY) { + /* - * For multicast mode, generate the session key - * and install in the key cache. For client - * mode, generate the session key for the - * unicast address. For server mode, the session - * key should already be in the key cache, since - * it was generated when the last request was - * sent. + * More on the autokey dance (AKD). A cookie is + * constructed from public and private values. + * For broadcast packets, the cookie is public + * (zero). For packets that match no + * association, the cookie is hashed from the + * addresses and private value. For server + * packets, the cookie was previously obtained + * from the server. For symmetric modes, the + * cookie was previously constructed using an + * agreement protocol; however, should PKI be + * unavailable, we construct a fake agreement as + * the EXOR of the peer and host cookies. + * + * hismode ephemeral persistent + * ======================================= + * active 0 cookie# + * passive 0% cookie# + * client sys cookie 0% + * server 0% sys cookie + * broadcast 0 0 + * + * # if unsync, 0 + * % can't happen */ if (hismode == MODE_BROADCAST) { + + /* + * For broadcaster, use the interface + * broadcast address when available; + * otherwise, use the unicast address + * found when the association was + * mobilized. + */ + pkeyid = 0; + if (rbufp->dstadr->bcast.sin_addr.s_addr + != 0) + dstadr_sin = + &rbufp->dstadr->bcast; + } else if (peer == NULL) { + pkeyid = session_key( + &rbufp->recv_srcadr, dstadr_sin, 0, + sys_private, 0); + } else { + pkeyid = peer->pcookie.key; + } + + /* + * The session key includes both the public + * values and cookie. In case of an extension + * field, the cookie used for authentication + * purposes is zero. Note the hash is saved for + * use later in the autokey mambo. + */ + if (authlen > LEN_PKT_NOMAC && pkeyid != 0) { + session_key(&rbufp->recv_srcadr, + dstadr_sin, skeyid, 0, 2); tkeyid = session_key( - ntohl((&rbufp->recv_srcadr)->sin_addr.s_addr), - ntohl(rbufp->dstadr->bcast.sin_addr.s_addr), - skeyid, (u_long)(4 * (1 << pkt->ppoll))); - } else if (hismode != MODE_SERVER) { + &rbufp->recv_srcadr, dstadr_sin, + skeyid, pkeyid, 0); + } else { tkeyid = session_key( - ntohl((&rbufp->recv_srcadr)->sin_addr.s_addr), - ntohl(rbufp->dstadr->sin.sin_addr.s_addr), - skeyid, (u_long)(4 * (1 << pkt->ppoll))); + &rbufp->recv_srcadr, dstadr_sin, + skeyid, pkeyid, 2); } } -#endif /* MD5 */ +#endif /* AUTOKEY */ /* * Compute the cryptosum. Note a clogging attack may - * succceed in bloating the key cache. + * succeed in bloating the key cache. If an autokey, + * purge it immediately, since we won't be needing it + * again. */ if (authdecrypt(skeyid, (u_int32 *)pkt, authlen, has_mac)) is_authentic = 1; else sys_badauth++; +#ifdef AUTOKEY + if (skeyid > NTP_MAXKEY) + authtrust(skeyid, 0); +#endif /* AUTOKEY */ #ifdef DEBUG if (debug) printf( - "receive: at %ld %s mode %d keyid %08lx mac %d auth %d\n", - current_time, ntoa(&rbufp->recv_srcadr), - hismode, skeyid, has_mac, is_authentic); + "receive: at %ld %s<-%s mode %d code %d keyid %08x len %d mac %d auth %d\n", + current_time, ntoa(dstadr_sin), + ntoa(&rbufp->recv_srcadr), hismode, retcode, + skeyid, authlen, has_mac, + is_authentic); #endif } /* - * Find the peer. This will return a null if this guy isn't in - * the database. + * The association matching rules are implemented by a set of + * routines and a table in ntp_peer.c. A packet matching an + * association is processed by that association. If not and + * certain conditions prevail, then an ephemeral association is + * mobilized: a broadcast packet mobilizes a broadcast client + * aassociation; a server packet mobilizes a client association; + * a symmetric active packet mobilizes a symmetric passive + * association. And, the adventure continues... */ - peer = findpeer(&rbufp->recv_srcadr, rbufp->dstadr, rbufp->fd, - hismode, &retcode); - /* - * The new association matching rules are driven by a table - * specified in ntp.h. We have replaced the *default* behaviour - * of replying to bogus packets in server mode in this version. - * A packet must now match an association in order to be - * processed. In the event that no association exists, then an - * association is mobilized if need be. Two different - * associations can be mobilized a) passive associations b) - * client associations due to broadcasts or manycasts. - */ - is_error = 0; switch (retcode) { case AM_FXMIT: /* - * If the client is configured purely as a broadcast - * client and not as an manycast server, it has no - * business being a server. Simply go home. Otherwise, - * send a MODE_SERVER response and go home. Note that we - * don't do a authentication check here, since we can't - * set the system clock; but, we do set the key ID to - * zero to tell the caller about this. + * This is a client mode packet not matching a known + * association. If from a manycast client we run a few + * sanity checks before deciding to send a unicast + * server response. Otherwise, it must be a client + * request, so send a server response and go home. */ - if (!sys_bclient || sys_manycastserver) { - if (is_authentic) - fast_xmit(rbufp, MODE_SERVER, skeyid); - else - fast_xmit(rbufp, MODE_SERVER, 0); + if (sys_manycastserver && (rbufp->dstadr->flags & + INT_MULTICAST)) { + + /* + * We are picky about responding to a + * manycaster. There is no reason to respond to + * a request if our time is worse than the + * manycaster. We certainly don't reply if not + * synchronized to proventic time. + */ + if (sys_peer == NULL) + return; + + /* + * We don't reply if the our stratum is greater + * than the manycaster. + */ + if (PKT_TO_STRATUM(pkt->stratum) < sys_stratum) + return; } /* - * We can't get here if an association is mobilized, so - * just toss the key, if appropriate. + * Note that we don't require an authentication check + * here, since we can't set the system clock; but, we do + * set the key ID to zero to tell the caller about this. */ - if (!is_mystic && skeyid > NTP_MAXKEY) - authtrust(skeyid, 0); - return; + if (is_authentic) + fast_xmit(rbufp, MODE_SERVER, skeyid, + restrict_mask); + else + fast_xmit(rbufp, MODE_SERVER, 0, restrict_mask); + return; case AM_MANYCAST: /* - * This could be in response to a multicast packet sent - * by the "manycast" mode association. Find peer based - * on the originate timestamp in the packet. Note that - * we don't mobilize a new association, unless the - * packet is properly authenticated. The response must - * be properly authenticated and it's darn funny of the - * manycaster isn't around now. + * This is a server mode packet returned in response to + * a client mode packet sent to a multicast group + * address. The originate timestamp is a good nonce to + * reliably associate the reply with what was sent. If + * there is no match, that's curious and could be an + * intruder attempting to clog, so we just ignore it. + * + * First, make sure the packet is authentic. If so and + * the manycast association is found, we mobilize a + * client mode association, copy pertinent variables + * from the manycast to the client mode association and + * wind up the spring. + * + * There is an implosion hazard at the manycast client, + * since the manycast servers send the server packet + * immediately. */ - if ((sys_authenticate && !is_authentic)) { - is_error = 1; - break; - } - peer2 = (struct peer *)findmanycastpeer(&pkt->org); - if (peer2 == 0) { - is_error = 1; - break; - } + if ((restrict_mask & (RES_DONTSERVE | RES_LIMITED | + RES_NOPEER)) || (sys_authenticate && + !is_authentic)) + return; + + peer2 = findmanycastpeer(rbufp); + if (peer2 == 0) + return; - /* - * Create a new association and copy the peer variables - * to it. If something goes wrong, carefully pry the new - * association away and return its marbles to the candy - * store. - */ peer = newpeer(&rbufp->recv_srcadr, rbufp->dstadr, MODE_CLIENT, PKT_VERSION(pkt->li_vn_mode), - NTP_MINDPOLL, NTP_MAXDPOLL, 0, skeyid); - if (peer == 0) { - is_error = 1; - break; - } - peer_config_manycast(peer2, peer); - break; - - case AM_ERR: - - /* - * Something bad happened. Dirty floor will be mopped by - * the code at the end of this adventure. - */ - is_error = 1; + sys_minpoll, NTP_MAXDPOLL, FLAG_IBURST | + (peer2->flags & (FLAG_AUTHENABLE | FLAG_SKEY)), + MDF_UCAST, 0, skeyid); + if (peer == NULL) + return; break; case AM_NEWPASS: /* - * Okay, we're going to keep him around. Allocate him - * some memory. But, don't do that unless the packet is - * properly authenticated. + * This is the first packet received from a symmetric + * active peer. First, make sure the packet is + * authentic. If so, mobilize a symmetric passive + * association. */ - if ((sys_authenticate && !is_authentic)) { - is_error = 1; - break; + if ((restrict_mask & (RES_DONTSERVE | RES_LIMITED | + RES_NOPEER)) || (sys_authenticate && + !is_authentic)) { + fast_xmit(rbufp, MODE_PASSIVE, 0, + restrict_mask); + return; } peer = newpeer(&rbufp->recv_srcadr, rbufp->dstadr, MODE_PASSIVE, PKT_VERSION(pkt->li_vn_mode), - NTP_MINDPOLL, NTP_MAXDPOLL, 0, skeyid); + sys_minpoll, NTP_MAXDPOLL, sys_authenticate ? + FLAG_AUTHENABLE : 0, MDF_UCAST, 0, skeyid); + if (peer == NULL) + return; break; case AM_NEWBCL: /* - * Broadcast client being set up now. Do this only if - * the packet is properly authenticated. + * This is the first packet received from a broadcast + * server. First, make sure the packet is authentic, not + * restricted and that we are a broadcast or multicast + * client. If so, mobilize a broadcast client + * association. */ - if ((restrict_mask & RES_NOPEER) || !sys_bclient || - (sys_authenticate && !is_authentic)) { - is_error = 1; - break; - } + if ((restrict_mask & (RES_DONTSERVE | RES_LIMITED | + RES_NOPEER)) || (sys_authenticate && + !is_authentic) || !sys_bclient) + return; + peer = newpeer(&rbufp->recv_srcadr, rbufp->dstadr, - MODE_MCLIENT, PKT_VERSION(pkt->li_vn_mode), - NTP_MINDPOLL, NTP_MAXDPOLL, 0, skeyid); - if (peer == 0) - break; - peer->flags |= FLAG_MCAST1 | FLAG_MCAST2 | FLAG_BURST; - peer->hmode = MODE_CLIENT; - break; + MODE_CLIENT, PKT_VERSION(pkt->li_vn_mode), + sys_minpoll, NTP_MAXDPOLL, FLAG_MCAST | + FLAG_IBURST | (sys_authenticate ? + FLAG_AUTHENABLE : 0), MDF_BCLNT, 0, skeyid); +#ifdef AUTOKEY +#ifdef PUBKEY + if (peer == NULL) + return; + if (peer->flags & FLAG_SKEY) + crypto_recv(peer, rbufp); +#endif /* PUBKEY */ +#endif /* AUTOKEY */ + return; case AM_POSSBCL: case AM_PROCPKT: /* - * It seems like it is okay to process the packet now + * Happiness and nothing broke. Earn some revenue. */ break; default: /* - * shouldn't be getting here, but simply return anyway! + * Invalid mode combination. Leave the island + * immediately. */ - is_error = 1; - } - if (is_error) { - - /* - * Error stub. If we get here, something broke. We - * scuttle the autokey if necessary and sink the ship. - * This can occur only upon mobilization, so we can - * throw the structure away without fear of breaking - * anything. - */ - if (!is_mystic && skeyid > NTP_MAXKEY) - authtrust(skeyid, 0); - if (peer != 0) - if (!(peer->flags & FLAG_CONFIG)) - unpeer(peer); #ifdef DEBUG if (debug) - printf("match error code %d assoc %d\n", - retcode, peer_associations); + printf("receive: bad protocol %d\n", retcode); #endif return; } /* - * If the peer isn't configured, set his keyid and authenable - * status based on the packet. + * If the peer isn't configured, set his authenable and autokey + * status based on the packet. Once the status is set, it can't + * be unset. It seems like a silly idea to do this here, rather + * in the configuration routine, but in some goofy cases the + * first packet sent cannot be authenticated and we need a way + * for the dude to change his mind. */ oflags = peer->flags; peer->timereceived = current_time; + peer->received++; if (!(peer->flags & FLAG_CONFIG) && has_mac) { peer->flags |= FLAG_AUTHENABLE; - if (skeyid > NTP_MAXKEY) { - if (peer->flags & FLAG_MCAST2) - peer->keyid = skeyid; - else - peer->flags |= FLAG_SKEY; - } +#ifdef AUTOKEY + if (skeyid > NTP_MAXKEY) + peer->flags |= FLAG_SKEY; +#endif /* AUTOKEY */ } /* - * Determine if this guy is basically trustable. If not, flush - * the bugger. If this is the first packet that is - * authenticated, flush the clock filter. This is to foil - * clogging attacks that might starve the poor dear. + * A valid packet must be from an authentic and allowed source. + * All packets must pass the authentication allowed tests. + * Autokey authenticated packets must pass additional tests and + * public-key authenticated packets must have the credentials + * verified. If all tests are passed, the packet is forwarded + * for processing. If not, the packet is discarded and the + * association demobilized if appropriate. */ peer->flash = 0; - if (is_authentic) + if (is_authentic) { peer->flags |= FLAG_AUTHENTIC; - else + } else { peer->flags &= ~FLAG_AUTHENTIC; - if (peer->hmode == MODE_BROADCAST && (restrict_mask & - RES_DONTTRUST)) - peer->flash |= TEST10; /* access denied */ + } + if (peer->hmode == MODE_BROADCAST && + (restrict_mask & RES_DONTTRUST)) /* test 4 */ + peer->flash |= TEST4; /* access denied */ if (peer->flags & FLAG_AUTHENABLE) { - if (!(peer->flags & FLAG_AUTHENTIC)) + if (!(peer->flags & FLAG_AUTHENTIC)) /* test 5 */ peer->flash |= TEST5; /* auth failed */ - else if (skeyid == 0) - peer->flash |= TEST9; /* peer not auth */ - else if (!(oflags & FLAG_AUTHENABLE)) { - peer_clear(peer); + else if (!(oflags & FLAG_AUTHENABLE)) report_event(EVNT_PEERAUTH, peer); - } } - if ((peer->flash & ~(u_int)TEST9) != 0) { - - /* - * The packet is bogus, so we throw it away before - * becoming a denial-of-service hazard. We don't throw - * the current association away if it is configured or - * if it has prior reachable friends. - */ - if (!is_mystic && skeyid > NTP_MAXKEY) - authtrust(skeyid, 0); - if (!(peer->flags & FLAG_CONFIG) && peer->reach == 0) - unpeer(peer); + if (peer->flash) { #ifdef DEBUG if (debug) - printf( - "invalid packet 0x%02x code %d assoc %d\n", - peer->flash, retcode, peer_associations); + printf("receive: bad auth %03x\n", peer->flash); #endif return; } -#ifdef MD5 +#ifdef AUTOKEY /* - * The autokey dance. The cha-cha requires that the hash of the - * current session key matches the previous key identifier. - * Heaps of trouble if the steps falter. + * More autokey dance. The rules of the cha-cha are as follows: + * + * 1. If there is no key or the key is not auto, do nothing. + * + * 2. If an extension field contains a verified signature, it is + * self-authenticated and we sit the dance. + * + * 3. If this is a server reply, check only to see that the + * transmitted key ID matches the received key ID. + * + * 4. Check to see that one or more hashes of the current key ID + * matches the previous key ID or ultimate original key ID + * obtained from the broadcaster or symmetric peer. If no + * match, sit the dance and wait for timeout. */ - if (skeyid > NTP_MAXKEY) { - int i; - - /* - * In the case of a new autokey, verify the hash matches - * one of the previous four hashes. If not, raise the - * authentication flasher and hope the next one works. - */ + if (peer->flags & FLAG_SKEY) { + peer->flash |= TEST10; + crypto_recv(peer, rbufp); + poll_update(peer, peer->hpoll); if (hismode == MODE_SERVER) { - peer->pkeyid = peer->keyid; - } else if (peer->flags & FLAG_MCAST2) { - if (peer->pkeyid > NTP_MAXKEY) - authtrust(peer->pkeyid, 0); - for (i = 0; i < 4 && tkeyid != peer->pkeyid; - i++) { - tkeyid = session_key( - ntohl((&rbufp->recv_srcadr)->sin_addr.s_addr), - ntohl(rbufp->dstadr->bcast.sin_addr.s_addr), - tkeyid, 0); - } + if (skeyid == peer->keyid) + peer->flash &= ~TEST10; + } else if (!peer->flash & TEST10) { + peer->pkeyid = skeyid; } else { - if (peer->pkeyid > NTP_MAXKEY) - authtrust(peer->pkeyid, 0); - for (i = 0; i < 4 && tkeyid != peer->pkeyid; - i++) { + int i; + + for (i = 0; ; i++) { + if (tkeyid == peer->pkeyid || + tkeyid == peer->recauto.key) { + peer->flash &= ~TEST10; + peer->pkeyid = skeyid; + break; + } + if (i > peer->recauto.seq) + break; tkeyid = session_key( - ntohl((&rbufp->recv_srcadr)->sin_addr.s_addr), - ntohl(rbufp->dstadr->sin.sin_addr.s_addr), - tkeyid, 0); + &rbufp->recv_srcadr, dstadr_sin, + tkeyid, pkeyid, 0); } } -#ifdef XXX /* temp until certificate code is mplemented */ - if (tkeyid != peer->pkeyid) - peer->flash |= TEST9; /* peer not authentic */ +#ifdef PUBKEY + + /* + * This is delicious. Ordinarily, we kick out all errors + * at this point; however, in symmetric mode and just + * warming up, an unsynchronized peer must inject the + * timestamps, even if it fails further up the road. So, + * let the dude by here, but only if the jerk is not yet + * reachable. After that, he's on his own. + */ + if (!(peer->flags & FLAG_PROVEN)) + peer->flash |= TEST11; + if (peer->flash && peer->reach) { +#ifdef DEBUG + if (debug) + printf("packet: bad autokey %03x\n", + peer->flash); #endif - peer->pkeyid = skeyid; + return; + } +#endif /* PUBKEY */ } -#endif /* MD5 */ +#endif /* AUTOKEY */ /* - * Gawdz, it's come to this. Process the dang packet. If - * something breaks and the association doesn't deserve to live, - * toss it. Be careful in active mode and return a packet - * anyway. + * We have survived the gaunt. Forward to the packet routine. If + * a symmetric passive association has been mobilized and the + * association doesn't deserve to live, it will die in the + * transmit routine if not reachable after timeout. */ - process_packet(peer, pkt, &(rbufp->recv_time)); - if (!(peer->flags & FLAG_CONFIG) && peer->reach == 0) { - if (peer->hmode == MODE_PASSIVE) { - if (is_authentic) - fast_xmit(rbufp, MODE_PASSIVE, skeyid); - else - fast_xmit(rbufp, MODE_PASSIVE, 0); - } - unpeer(peer); - } + process_packet(peer, pkt, &rbufp->recv_time); } @@ -703,7 +835,7 @@ receive( * reasonable expectation that we will be having a long term * relationship with this host. */ -int +void process_packet( register struct peer *peer, register struct pkt *pkt, @@ -715,10 +847,13 @@ process_packet( double dtemp; l_fp p_rec, p_xmt, p_org, p_reftime; l_fp ci; - int pmode; + int pmode, pleap, pstratum; /* - * Swap header fields and keep the books. + * Swap header fields and keep the books. The books amount to + * the receive timestamp and poll interval in the header. We + * need these even if there are other problems in order to crank + * up the state machine. */ sys_processed++; peer->processed++; @@ -731,84 +866,115 @@ process_packet( NTOHL_FP(&pkt->org, &p_org); else p_org = peer->rec; - peer->rec = *recv_ts; - peer->ppoll = pkt->ppoll; - pmode = PKT_MODE(pkt->li_vn_mode); /* - * Test for old or duplicate packets (tests 1 through 3). + * Test for old, duplicate or unsynch packets (tests 1-3). */ + peer->rec = *recv_ts; + pmode = PKT_MODE(pkt->li_vn_mode); + pleap = PKT_LEAP(pkt->li_vn_mode); + pstratum = PKT_TO_STRATUM(pkt->stratum); if (L_ISHIS(&peer->org, &p_xmt)) /* count old packets */ peer->oldpkt++; - if (L_ISEQU(&peer->org, &p_xmt)) /* test 1 */ - peer->flash |= TEST1; /* duplicate packet */ - if (PKT_MODE(pkt->li_vn_mode) != MODE_BROADCAST) { - if (!L_ISEQU(&peer->xmt, &p_org)) { /* test 2 */ - peer->bogusorg++; - peer->flash |= TEST2; /* bogus packet */ - } - if (L_ISZERO(&p_rec) || L_ISZERO(&p_org)) - peer->flash |= TEST3; /* unsynchronized */ - } else { - if (L_ISZERO(&p_org)) - peer->flash |= TEST3; /* unsynchronized */ + if (L_ISEQU(&peer->org, &p_xmt)) /* 1 */ + peer->flash |= TEST1; /* dupe */ + if (pmode != MODE_BROADCAST) { + if (!L_ISEQU(&peer->xmt, &p_org)) /* 2 */ + peer->flash |= TEST2; /* bogus */ + if (L_ISZERO(&p_rec) || L_ISZERO(&p_org)) /* test 3 */ + peer->flash |= TEST3; /* unsynch */ } + if (L_ISZERO(&p_xmt)) /* 3 */ + peer->flash |= TEST3; /* unsynch */ peer->org = p_xmt; /* - * Test for valid header (tests 5 through 10) + * If tests 1-3 fail, the packet is discarded leaving only the + * receive and origin timestamps and poll interval, which is + * enough to get the protocol started. + */ + if (peer->flash) { +#ifdef DEBUG + if (debug) + printf("packet: bad data %03x\n", + peer->flash); +#endif + return; + } + + /* + * A kiss-of-death (kod) packet is returned by a server in case + * the client is denied access. It consists of the client + * request packet with the leap bits indicating never + * synchronized, stratum zero and reference ID field the ASCII + * string "DENY". If the packet originate timestamp matches the + * association transmit timestamp the kod is legitimate. If the + * peer leap bits indicate never synchronized, this must be + * access deny and the association is disabled; otherwise this + * must be a limit reject. In either case a naughty message is + * forced to the system log. + */ + if (pleap == LEAP_NOTINSYNC && pstratum >= STRATUM_UNSPEC && + memcmp(&pkt->refid, "DENY", 4) == 0) { + if (peer->leap == LEAP_NOTINSYNC) { + peer->stratum = STRATUM_UNSPEC; + peer->flash |= TEST4; + memcpy(&peer->refid, &pkt->refid, 4); + msyslog(LOG_INFO, "access denied"); + } else { + msyslog(LOG_INFO, "limit reject"); + } + return; + } + + /* + * Test for valid peer data (tests 6-8) */ ci = p_xmt; L_SUB(&ci, &p_reftime); LFPTOD(&ci, dtemp); - if (PKT_LEAP(pkt->li_vn_mode) == LEAP_NOTINSYNC || /* test 6 */ - PKT_TO_STRATUM(pkt->stratum) >= NTP_MAXSTRATUM || - dtemp < 0) - peer->flash |= TEST6; /* peer clock unsynchronized */ - if (!(peer->flags & FLAG_CONFIG) && sys_peer != 0) { /* test 7 */ - if (PKT_TO_STRATUM(pkt->stratum) > sys_stratum) { - peer->flash |= TEST7; /* peer stratum too high */ + if (pleap == LEAP_NOTINSYNC || /* 6 */ + pstratum >= STRATUM_UNSPEC || dtemp < 0) + peer->flash |= TEST6; /* bad synch */ + if (!(peer->flags & FLAG_CONFIG) && sys_peer != NULL) { /* 7 */ + if (pstratum > sys_stratum && pmode != MODE_ACTIVE) { + peer->flash |= TEST7; /* bad stratum */ sys_badstratum++; } } - if (fabs(p_del) >= MAXDISPERSE /* test 8 */ - || p_disp >= MAXDISPERSE) - peer->flash |= TEST8; /* delay/dispersion too high */ - - /* - * If the packet header is invalid (tests 5 through 10), exit. - * XXX we let TEST9 sneak by until the certificate code is - * implemented, but only to mobilize the association. - */ - if (peer->flash & (TEST5 | TEST6 | TEST7 | TEST8 | TEST10)) { + if (p_del < 0 || p_disp < 0 || p_del / /* 8 */ + 2 + p_disp >= MAXDISPERSE) + peer->flash |= TEST8; /* bad peer distance */ + if (peer->flash) { #ifdef DEBUG if (debug) - printf( - "invalid packet header 0x%02x mode %d\n", - peer->flash, pmode); + printf("packet: bad header %03x\n", + peer->flash); #endif - return (0); + return; } /* - * Valid header; update our state. + * The header is valid. Capture the remaining header values and + * mark as reachable. */ - record_raw_stats(&peer->srcadr, &peer->dstadr->sin, - &p_org, &p_rec, &p_xmt, &peer->rec); - - peer->leap = PKT_LEAP(pkt->li_vn_mode); - peer->pmode = pmode; /* unspec */ - peer->stratum = PKT_TO_STRATUM(pkt->stratum); + record_raw_stats(&peer->srcadr, &peer->dstadr->sin, &p_org, + &p_rec, &p_xmt, &peer->rec); + peer->leap = pleap; + peer->pmode = pmode; + peer->stratum = pstratum; + peer->ppoll = pkt->ppoll; peer->precision = pkt->precision; peer->rootdelay = p_del; peer->rootdispersion = p_disp; peer->refid = pkt->refid; peer->reftime = p_reftime; - if (peer->reach == 0) { + if (!(peer->reach)) { report_event(EVNT_REACH, peer); peer->timereachable = current_time; } peer->reach |= 1; + peer->unreach = 0; poll_update(peer, peer->hpoll); /* @@ -829,34 +995,25 @@ process_packet( t23 = p_rec; /* compute t2 - t3 */ L_SUB(&t23, &p_org); ci = t10; - p_disp = CLOCK_PHI * (peer->rec.l_ui - p_org.l_ui); + p_disp = clock_phi * (peer->rec.l_ui - p_org.l_ui); /* * If running in a broadcast association, the clock offset is * (t1 - t0) corrected by the one-way delay, but we can't - * measure that directly; therefore, we start up in - * client/server mode, calculate the clock offset, using the - * engineered refinement algorithms, while also receiving - * broadcasts. When a broadcast is received in client/server - * mode, we calculate a correction factor to use after switching - * back to broadcast mode. We know NTP_SKEWFACTOR == 16, which - * accounts for the simplified ei calculation. - * - * If FLAG_MCAST2 is set, we are a broadcast/multicast client. - * If FLAG_MCAST1 is set, we haven't calculated the propagation - * delay. If hmode is MODE_CLIENT, we haven't set the local - * clock in client/server mode. Initially, we come up - * MODE_CLIENT. When the clock is first updated and FLAG_MCAST2 - * is set, we switch from MODE_CLIENT to MODE_BCLIENT. + * measure that directly. Therefore, we start up in MODE_CLIENT + * mode, set FLAG_MCAST and exchange eight messages to determine + * the clock offset. When the last message is sent, we switch to + * MODE_BCLIENT mode. The next broadcast message after that + * computes the broadcast offset and clears FLAG_MCAST. */ if (pmode == MODE_BROADCAST) { - if (peer->flags & FLAG_MCAST1) { - if (peer->hmode == MODE_BCLIENT) - peer->flags &= ~FLAG_MCAST1; + if (peer->flags & FLAG_MCAST) { LFPTOD(&ci, p_offset); peer->estbdelay = peer->offset - p_offset; - return (1); + if (peer->hmode == MODE_CLIENT) + return; + peer->flags &= ~FLAG_MCAST; } DTOLFP(peer->estbdelay, &t10); L_ADD(&ci, &t10); @@ -867,32 +1024,29 @@ process_packet( L_SUB(&t23, &t10); LFPTOD(&t23, p_del); } + p_del = max(p_del, LOGTOD(sys_precision)); LFPTOD(&ci, p_offset); - if (fabs(p_del) >= MAXDISPERSE || p_disp >= MAXDISPERSE) /* test 4 */ - peer->flash |= TEST4; /* delay/dispersion too big */ + if ((peer->rootdelay + p_del) / 2. + peer->rootdispersion + + p_disp >= MAXDISPERSE) /* 9 */ + peer->flash |= TEST9; /* bad peer distance */ /* - * If the packet data are invalid (tests 1 through 4), exit. + * If any flasher bits remain set at this point, abandon ship. + * Otherwise, forward to the clock filter. */ if (peer->flash) { #ifdef DEBUG if (debug) - printf("invalid packet data 0x%02x mode %d\n", - peer->flash, pmode); + printf("packet: bad packet data %03x\n", + peer->flash); #endif - return(1); + return; } - - - /* - * This one is valid. Mark it so, give it to clock_filter(). - */ - clock_filter(peer, p_offset, p_del, fabs(p_disp)); + clock_filter(peer, p_offset, p_del, p_disp); clock_select(); record_peer_stats(&peer->srcadr, ctlpeerstatus(peer), peer->offset, peer->delay, peer->disp, - SQRT(peer->variance)); - return(1); + SQRT(peer->jitter)); } @@ -904,15 +1058,13 @@ clock_update(void) { u_char oleap; u_char ostratum; - int i; - struct peer *peer; /* * Reset/adjust the system clock. Do this only if there is a * system peer and we haven't seen that peer lately. Watch for * timewarps here. */ - if (sys_peer == 0) + if (sys_peer == NULL) return; if (sys_peer->pollsw == FALSE || sys_peer->burst > 0) return; @@ -924,60 +1076,58 @@ clock_update(void) #endif oleap = sys_leap; ostratum = sys_stratum; - switch (local_clock(sys_peer, sys_offset, sys_epsil)) { + switch (local_clock(sys_peer, sys_offset, sys_syserr)) { - case -1: - /* - * Clock is too screwed up. Just exit for now. - */ + /* + * Clock is too screwed up. Just exit for now. + */ + case -1: report_event(EVNT_SYSFAULT, (struct peer *)0); exit(1); /*NOTREACHED*/ - case 1: - /* - * Clock was stepped. Clear filter registers - * of all peers. - */ - for (i = 0; i < HASH_SIZE; i++) { - for (peer = peer_hash[i]; peer != 0; - peer =peer->next) - peer_clear(peer); - } - NLOG(NLOG_SYNCSTATUS) - msyslog(LOG_INFO, "synchronisation lost"); - sys_peer = 0; + /* + * Clock was stepped. Flush all time values of all peers. + */ + case 1: + clear_all(); + sys_peer = NULL; sys_stratum = STRATUM_UNSPEC; + sys_poll = NTP_MINPOLL; + NLOG(NLOG_SYNCSTATUS) + msyslog(LOG_INFO, "synchronisation lost"); report_event(EVNT_CLOCKRESET, (struct peer *)0); break; - default: - /* - * Update the system stratum, leap bits, root delay, - * root dispersion, reference ID and reference time. We - * also update select dispersion and max frequency - * error. - */ + /* + * Update the system stratum, leap bits, root delay, root + * dispersion, reference ID and reference time. We also update + * select dispersion and max frequency error. If the leap + * changes, we gotta reroll the keys. + */ + default: sys_stratum = sys_peer->stratum + 1; if (sys_stratum == 1) sys_refid = sys_peer->refid; else sys_refid = sys_peer->srcadr.sin_addr.s_addr; sys_reftime = sys_peer->rec; - sys_rootdelay = sys_peer->rootdelay + - fabs(sys_peer->delay); + sys_rootdelay = sys_peer->rootdelay + sys_peer->delay; sys_leap = leap_consensus; } - if (oleap != sys_leap) + if (oleap == LEAP_NOTINSYNC) { report_event(EVNT_SYNCCHG, (struct peer *)0); +#ifdef AUTOKEY + expire_all(); +#endif /* AUTOKEY */ + } if (ostratum != sys_stratum) report_event(EVNT_PEERSTCHG, (struct peer *)0); } /* - * poll_update - update peer poll interval. See Section 3.4.9 of the - * spec. + * poll_update - update peer poll interval */ void poll_update( @@ -985,46 +1135,83 @@ poll_update( int hpoll ) { - long update; +#ifdef AUTOKEY + int oldpoll; +#endif /* AUTOKEY */ /* - * The wiggle-the-poll-interval dance. Broadcasters dance only - * the minpoll beat. Reference clock partners sit this one out. - * Dancers surviving the clustering algorithm beat to the system - * clock. Broadcast clients are usually lead by their broadcast - * partner, but faster in the initial mating dance. + * A little foxtrot to determine what controls the poll + * interval. If the peer is reachable, but the last four polls + * have not been answered, use the minimum. If declared + * truechimer, use the system poll interval. This allows each + * association to ramp up the poll interval for useless sources + * and to clamp it to the minimum when first starting up. */ - if (peer->hmode == MODE_BROADCAST) { +#ifdef AUTOKEY + oldpoll = peer->kpoll; +#endif /* AUTOKEY */ + if (hpoll > peer->maxpoll) + peer->hpoll = peer->maxpoll; + else if (hpoll < peer->minpoll) peer->hpoll = peer->minpoll; - } else if (peer->flags & FLAG_SYSPEER) { - peer->hpoll = sys_poll; - } else { - if (hpoll > peer->maxpoll) - peer->hpoll = peer->maxpoll; - else if (hpoll < peer->minpoll) - peer->hpoll = peer->minpoll; - else - peer->hpoll = hpoll; - } + else + peer->hpoll = hpoll; + + /* + * Bit of adventure here. If during a burst and not timeout, + * just slink away. If timeout, figure what the next timeout + * should be. If IBURST or a reference clock, use one second. If + * not and the dude was reachable during the previous poll + * interval, randomize over 1-4 seconds; otherwise, randomize + * over 15-18 seconds. This is to give time for a modem to + * complete the call, for example. If not during a burst, + * randomize over the poll interval -1 to +2 seconds. + * + * In case of manycast server, make the poll interval, which is + * axtually the manycast beacon interval, eight times the system + * poll interval. Normally when the host poll interval settles + * up to 17.1 s, the beacon interval settles up to 2.3 hours. + */ if (peer->burst > 0) { if (peer->nextdate != current_time) return; - if (peer->flags & FLAG_REFCLOCK) +#ifdef REFCLOCK + else if (peer->flags & FLAG_REFCLOCK) peer->nextdate++; +#endif else if (peer->reach & 0x1) peer->nextdate += RANDPOLL(BURST_INTERVAL2); else peer->nextdate += RANDPOLL(BURST_INTERVAL1); + } else if (peer->cast_flags & MDF_ACAST) { + if (sys_survivors < NTP_MINCLOCK) + peer->kpoll = peer->hpoll; + else + peer->kpoll = peer->hpoll + 3; + peer->nextdate = peer->outdate + RANDPOLL(peer->kpoll); } else { - update = max(min(peer->ppoll, peer->hpoll), + peer->kpoll = max(min(peer->ppoll, peer->hpoll), peer->minpoll); - peer->nextdate = peer->outdate + RANDPOLL(update); + peer->nextdate = peer->outdate + RANDPOLL(peer->kpoll); } + if (peer->nextdate < current_time) + peer->nextdate = current_time; +#ifdef AUTOKEY + /* + * Bit of crass arrogance at this point. If the poll interval + * has changed and we have a keylist, the lifetimes in the + * keylist are probably bogus. In this case purge the keylist + * and regenerate it later. + */ + if (peer->kpoll != oldpoll) + key_expire(peer); +#endif /* AUTOKEY */ #ifdef DEBUG if (debug > 1) - printf("poll_update: at %lu %s poll %d burst %d last %lu next %lu\n", - current_time, ntoa(&peer->srcadr), hpoll, - peer->burst, peer->outdate, peer->nextdate); + printf("poll_update: at %lu %s flags %04x poll %d burst %d last %lu next %lu\n", + current_time, ntoa(&peer->srcadr), peer->flags, + peer->kpoll, peer->burst, peer->outdate, + peer->nextdate); #endif } @@ -1038,28 +1225,72 @@ peer_clear( ) { register int i; + u_long u_rand; + /* + * If cryptographic credentials have been acquired, toss them to + * Valhalla. Note that autokeys are ephemeral, in that they are + * tossed immediately upon use. Therefore, the keylist can be + * purged anytime without needing to preserve random keys. Note + * that, if the peer is purged, the cryptographic variables are + * purged, too. This makes it much harder to sneak in some + * unauthenticated data in the clock filter. + */ +#ifdef DEBUG + if (debug) + printf("peer_clear: at %ld assoc ID %d\n", current_time, + peer->associd); +#endif +#ifdef AUTOKEY + key_expire(peer); +#ifdef PUBKEY + if (peer->keystr != NULL) + free(peer->keystr); + if (peer->pubkey.ptr != NULL) + free(peer->pubkey.ptr); + if (peer->certif.ptr != NULL) + free(peer->certif.ptr); +#endif /* PUBKEY */ +#endif /* AUTOKEY */ memset(CLEAR_TO_ZERO(peer), 0, LEN_CLEAR_TO_ZERO); + + /* + * If he dies as a broadcast client, he comes back to life as + * a broadcast client in client mode in order to recover the + * initial autokey values. Note that there is no need to call + * clock_select(), since the perp has already been voted off + * the island at this point. + */ + if (peer->cast_flags & MDF_BCLNT) { + peer->flags |= FLAG_MCAST; + peer->hmode = MODE_CLIENT; + } + peer->flags &= ~(FLAG_AUTOKEY | FLAG_ASSOC); peer->estbdelay = sys_bdelay; - peer->hpoll = peer->minpoll; + peer->hpoll = peer->kpoll = peer->minpoll; + peer->ppoll = peer->maxpoll; peer->pollsw = FALSE; - peer->variance = MAXDISPERSE; + peer->jitter = MAXDISPERSE; peer->epoch = current_time; +#ifdef REFCLOCK + if (!(peer->flags & FLAG_REFCLOCK)) { + peer->leap = LEAP_NOTINSYNC; + peer->stratum = STRATUM_UNSPEC; + } +#endif for (i = 0; i < NTP_SHIFT; i++) { peer->filter_order[i] = i; peer->filter_disp[i] = MAXDISPERSE; peer->filter_epoch[i] = current_time; } - poll_update(peer, peer->minpoll); /* - * Since we have a chance to correct possible funniness in - * our selection of interfaces on a multihomed host, do so - * by setting us to no particular interface. - * WARNING: do so only in non-broadcast mode! + * Randomize the first poll over 1-16s to avoid bunching. */ - if (peer->hmode != MODE_BROADCAST) - peer->dstadr = any_interface; + peer->update = peer->outdate = current_time; + u_rand = RANDOM; + peer->nextdate = current_time + (u_rand & ((1 << + BURST_INTERVAL1) - 1)) + 1; } @@ -1069,130 +1300,172 @@ peer_clear( */ void clock_filter( - register struct peer *peer, - double sample_offset, - double sample_delay, - double sample_disp + register struct peer *peer, /* peer structure pointer */ + double sample_offset, /* clock offset */ + double sample_delay, /* roundtrip delay */ + double sample_disp /* dispersion */ ) { - register int i, j, k, n = 0; - register u_char *ord; - double distance[NTP_SHIFT]; - double x, y, z, off; + double dst[NTP_SHIFT]; /* distance vector */ + int ord[NTP_SHIFT]; /* index vector */ + register int i, j, k, m; + double dsp, jit, dtemp, etemp; /* - * Update error bounds and calculate distances. Also initialize - * sort index vector. + * Shift the new sample into the register and discard the oldest + * one. The new offset and delay come directly from the + * timestamp calculations. The dispersion grows from the last + * outbound packet or reference clock update to the present time + * and increased by the sum of the peer precision and the system + * precision. The delay can sometimes swing negative due to + * frequency skew, so it is clamped non-negative. */ - x = CLOCK_PHI * (current_time - peer->update); - peer->update = current_time; - ord = peer->filter_order; + dsp = min(LOGTOD(peer->precision) + LOGTOD(sys_precision) + + sample_disp, MAXDISPERSE); j = peer->filter_nextpt; - for (i = 0; i < NTP_SHIFT; i++) { - peer->filter_disp[j] += x; - if (peer->filter_disp[j] > MAXDISPERSE) - peer->filter_disp[j] = MAXDISPERSE; - distance[i] = fabs(peer->filter_delay[j]) / 2 + - peer->filter_disp[j]; - ord[i] = j; - if (--j < 0) - j += NTP_SHIFT; - } + peer->filter_offset[j] = sample_offset; + peer->filter_delay[j] = max(0, sample_delay); + peer->filter_disp[j] = dsp; + peer->filter_epoch[j] = current_time; + j++; j %=NTP_SHIFT; + peer->filter_nextpt = j; /* - * Insert the new sample at the beginning of the register. + * Update dispersions since the last update and at the same + * time initialize the distance and index lists. The distance + * list uses a compound metric. If the sample is valid and + * younger than the minimum Allan intercept, use delay; + * otherwise, use biased dispersion. */ - peer->filter_offset[peer->filter_nextpt] = sample_offset; - peer->filter_delay[peer->filter_nextpt] = sample_delay; - x = LOGTOD(peer->precision) + LOGTOD(sys_precision) + - sample_disp; - peer->filter_disp[peer->filter_nextpt] = min(x, MAXDISPERSE); - peer->filter_epoch[peer->filter_nextpt] = current_time; - distance[0] = min(x + fabs(sample_delay) / 2, MAXDISTANCE); - peer->filter_nextpt++; - if (peer->filter_nextpt >= NTP_SHIFT) - peer->filter_nextpt = 0; + dtemp = clock_phi * (current_time - peer->update); + peer->update = current_time; + for (i = NTP_SHIFT - 1; i >= 0; i--) { + if (i != 0) { + peer->filter_disp[j] += dtemp; + if (peer->filter_disp[j] > MAXDISPERSE) + peer->filter_disp[j] = MAXDISPERSE; + } + if (peer->filter_disp[j] >= MAXDISPERSE) + dst[i] = MAXDISPERSE; + else if (peer->update - peer->filter_epoch[j] > + allan_xpt) + dst[i] = MAXDISTANCE + peer->filter_disp[j]; + else + dst[i] = peer->filter_delay[j]; + ord[i] = j; + j++; j %= NTP_SHIFT; + } - /* - * Sort the samples in the register by distance. The winning - * sample will be in ord[0]. Sort the samples only if they - * are younger than the Allen intercept. + /* + * Sort the samples in both lists by distance. */ - y = min(allan_xpt, NTP_SHIFT * ULOGTOD(sys_poll)); - for (n = 0; n < NTP_SHIFT && current_time - - peer->filter_epoch[ord[n]] <= y; n++) { - for (j = 0; j < n; j++) { - if (distance[j] > distance[n]) { - x = distance[j]; + for (i = 1; i < NTP_SHIFT; i++) { + for (j = 0; j < i; j++) { + if (dst[j] > dst[i]) { k = ord[j]; - distance[j] = distance[n]; - ord[j] = ord[n]; - distance[n] = x; - ord[n] = k; + ord[j] = ord[i]; + ord[i] = k; + etemp = dst[j]; + dst[j] = dst[i]; + dst[i] = etemp; } } - } + } + + /* + * Copy the index list to the association structure so ntpq + * can see it later. Prune the distance list to samples less + * than MAXDISTANCE, but keep at least two valid samples for + * jitter calculation. + */ + m = 0; + for (i = 0; i < NTP_SHIFT; i++) { + peer->filter_order[i] = ord[i]; + if (dst[i] >= MAXDISPERSE || (m >= 2 && dst[i] >= + MAXDISTANCE)) + continue; + m++; + } /* - * Compute the error bound and standard error. + * Compute the dispersion and jitter squares. The dispersion + * is weighted exponentially by NTP_FWEIGHT (0.5) so it is + * normalized close to 1.0. The jitter is the mean of the square + * differences relative to the lowest delay sample. If no + * acceptable samples remain in the shift register, quietly + * tiptoe home leaving only the + * dispersion. */ - x = y = z = off = 0.; + jit = 0; + peer->disp = 0; + k = ord[0]; for (i = NTP_SHIFT - 1; i >= 0; i--) { - x = NTP_FWEIGHT * (x + peer->filter_disp[ord[i]]); - if (i < n) { - z += 1. / distance[i]; - off += peer->filter_offset[ord[i]] / - distance[i]; - y += DIFF(peer->filter_offset[ord[i]], - peer->filter_offset[ord[0]]); - } + + j = ord[i]; + peer->disp = NTP_FWEIGHT * (peer->disp + + peer->filter_disp[j]); + if (i < m) + jit += DIFF(peer->filter_offset[j], + peer->filter_offset[k]); } - peer->delay = peer->filter_delay[ord[0]]; - peer->variance = min(y / n, MAXDISPERSE); - peer->disp = min(x, MAXDISPERSE); - peer->epoch = current_time; - x = peer->offset; - if (peer->flags & FLAG_BURST) - peer->offset = off / z; - else - peer->offset = peer->filter_offset[ord[0]]; + + /* + * If no acceptable samples remain in the shift register, + * quietly tiptoe home leaving only the dispersion. Otherwise, + * save the offset, delay and jitter average. Note the jitter + * must not be less than the system precision. + */ + if (m == 0) + return; + etemp = peer->offset; + peer->offset = peer->filter_offset[k]; + peer->delay = peer->filter_delay[k]; + if (m > 1) + jit /= m - 1; + peer->jitter = max(jit, SQUARE(LOGTOD(sys_precision))); /* * A new sample is useful only if it is younger than the last * one used. */ - if (peer->filter_epoch[ord[0]] > peer->epoch) { + if (peer->filter_epoch[k] <= peer->epoch) { #ifdef DEBUG if (debug) printf("clock_filter: discard %lu\n", - peer->filter_epoch[ord[0]] - peer->epoch); + peer->epoch - peer->filter_epoch[k]); #endif return; } /* - * If the offset exceeds the dispersion by CLOCK_SGATE and the - * interval since the last update is less than twice the system - * poll interval, consider the update a popcorn spike and ignore - * it. + * If the difference between the last offset and the current one + * exceeds the jitter by CLOCK_SGATE (4) and the interval since + * the last update is less than twice the system poll interval, + * consider the update a popcorn spike and ignore it. */ - if (fabs(x - peer->offset) > CLOCK_SGATE && - peer->filter_epoch[ord[0]] - peer->epoch < (1 << - (sys_poll + 1))) { + if (m > 1 && fabs(peer->offset - etemp) > SQRT(peer->jitter) * + CLOCK_SGATE && peer->filter_epoch[k] - peer->epoch < + (1 << (sys_poll + 1))) { #ifdef DEBUG if (debug) - printf("clock_filter: popcorn spike %.6f\n", x); + printf("clock_filter: n %d popcorn spike %.6f jitter %.6f\n", + m, peer->offset, SQRT(peer->jitter)); #endif return; } - peer->epoch = peer->filter_epoch[ord[0]]; + + /* + * The mitigated sample statistics are saved for later + * processing, but can be processed only once. + */ + peer->epoch = peer->filter_epoch[k]; peer->pollsw = TRUE; #ifdef DEBUG if (debug) printf( - "clock_filter: offset %.6f delay %.6f disp %.6f std %.6f, age %lu\n", - peer->offset, peer->delay, peer->disp, - SQRT(peer->variance), current_time - peer->epoch); + "clock_filter: n %d off %.6f del %.6f dsp %.6f jit %.6f, age %lu\n", + m, peer->offset, peer->delay, peer->disp, + SQRT(peer->jitter), peer->update - peer->epoch); #endif } @@ -1204,35 +1477,34 @@ void clock_select(void) { register struct peer *peer; - int i; - int nlist, nl3; + int i, j, k, n; + int nreach, nlist, nl3; double d, e, f; - int j; - int n; - int allow, found, k; + int allow, found, sw; double high, low; double synch[NTP_MAXCLOCK], error[NTP_MAXCLOCK]; struct peer *osys_peer; - struct peer *typeacts = 0; - struct peer *typelocal = 0; - struct peer *typepps = 0; - struct peer *typeprefer = 0; - struct peer *typesystem = 0; + struct peer *typeacts = NULL; + struct peer *typelocal = NULL; + struct peer *typepps = NULL; + struct peer *typesystem = NULL; static int list_alloc = 0; static struct endpoint *endpoint = NULL; - static int *index = NULL; + static int *indx = NULL; static struct peer **peer_list = NULL; static u_int endpoint_size = 0; - static u_int index_size = 0; + static u_int indx_size = 0; static u_int peer_list_size = 0; /* - * Initialize. If a prefer peer does not survive this thing, - * the pps_update switch will remain zero. + * Initialize and create endpoint, index and peer lists big + * enough to handle all associations. */ - pps_update = 0; - nlist = 0; + osys_peer = sys_peer; + sys_peer = NULL; + sys_prefer = NULL; + nreach = nlist = 0; low = 1e9; high = -1e9; for (n = 0; n < HASH_SIZE; n++) @@ -1240,49 +1512,58 @@ clock_select(void) if (nlist > list_alloc) { if (list_alloc > 0) { free(endpoint); - free(index); + free(indx); free(peer_list); } while (list_alloc < nlist) { list_alloc += 5; - endpoint_size += 5 * 3 * sizeof *endpoint; - index_size += 5 * 3 * sizeof *index; - peer_list_size += 5 * sizeof *peer_list; + endpoint_size += 5 * 3 * sizeof(*endpoint); + indx_size += 5 * 3 * sizeof(*indx); + peer_list_size += 5 * sizeof(*peer_list); } endpoint = (struct endpoint *)emalloc(endpoint_size); - index = (int *)emalloc(index_size); + indx = (int *)emalloc(indx_size); peer_list = (struct peer **)emalloc(peer_list_size); } /* - * This first chunk of code is supposed to go through all - * peers we know about to find the peers which are most likely - * to succeed. We run through the list doing the sanity checks - * and trying to insert anyone who looks okay. + * Initially, we populate the island with all the rifraff peers + * that happen to be lying around. Those with seriously + * defective clocks are immediately booted off the island. Then, + * the falsetickers are culled and put to sea. The truechimers + * remaining are subject to repeated rounds where the most + * unpopular at each round is kicked off. When the population + * has dwindled to NTP_MINCLOCK (3), the survivors split a + * million bucks and collectively crank the chimes. */ nlist = nl3 = 0; /* none yet */ for (n = 0; n < HASH_SIZE; n++) { - for (peer = peer_hash[n]; peer != 0; peer = peer->next) { + for (peer = peer_hash[n]; peer != NULL; peer = + peer->next) { peer->flags &= ~FLAG_SYSPEER; peer->status = CTL_PST_SEL_REJECT; - if (peer->flags & FLAG_NOSELECT) - continue; /* noselect (survey) */ - if (peer->reach == 0) - continue; /* unreachable */ - if (peer->stratum > 1 && peer->refid == - peer->dstadr->sin.sin_addr.s_addr) - continue; /* sync loop */ - if (root_distance(peer) >= MAXDISTANCE + 2 * - CLOCK_PHI * ULOGTOD(sys_poll)) { - peer->seldisptoolarge++; - continue; /* noisy or broken */ - } /* - * Don't allow the local-clock or acts drivers + * A peer leaves the island immediately if + * unreachable, synchronized to us or suffers + * excessive root distance. Careful with the + * root distance, since the poll interval can + * increase to a day and a half. + */ + if (!peer->reach || (peer->stratum > 1 && + peer->refid == + peer->dstadr->sin.sin_addr.s_addr) || + peer->stratum >= STRATUM_UNSPEC || + (root_distance(peer) >= MAXDISTANCE + 2 * + clock_phi * ULOGTOD(sys_poll))) + continue; + + /* + * Don't allow the local clock or modem drivers * in the kitchen at this point, unless the * prefer peer. Do that later, but only if - * nobody else is around. + * nobody else is around. These guys are all + * configured, so we never throw them away. */ if (peer->refclktype == REFCLK_LOCALCLOCK #if defined(VMS) && defined(VMS_LOCALUNIT) @@ -1301,9 +1582,11 @@ clock_select(void) } /* - * If we get this far, we assume the peer is - * acceptable. + * If we get this far, the peer can stay on the + * island, but does not yet have the immunity + * idol. */ + nreach++; peer->status = CTL_PST_SEL_SANE; peer_list[nlist++] = peer; @@ -1315,40 +1598,41 @@ clock_select(void) f = root_distance(peer); e = e + f; for (i = nl3 - 1; i >= 0; i--) { - if (e >= endpoint[index[i]].val) + if (e >= endpoint[indx[i]].val) break; - index[i + 3] = index[i]; + indx[i + 3] = indx[i]; } - index[i + 3] = nl3; + indx[i + 3] = nl3; endpoint[nl3].type = 1; endpoint[nl3++].val = e; e = e - f; /* Center point */ for ( ; i >= 0; i--) { - if (e >= endpoint[index[i]].val) + if (e >= endpoint[indx[i]].val) break; - index[i + 2] = index[i]; + indx[i + 2] = indx[i]; } - index[i + 2] = nl3; + indx[i + 2] = nl3; endpoint[nl3].type = 0; endpoint[nl3++].val = e; e = e - f; /* Lower end */ for ( ; i >= 0; i--) { - if (e >= endpoint[index[i]].val) + if (e >= endpoint[indx[i]].val) break; - index[i + 1] = index[i]; + indx[i + 1] = indx[i]; } - index[i + 1] = nl3; + indx[i + 1] = nl3; endpoint[nl3].type = -1; endpoint[nl3++].val = e; } } #ifdef DEBUG - if (debug > 1) + if (debug > 2) for (i = 0; i < nl3; i++) - printf("select: endpoint %2d %.6f\n", - endpoint[index[i]].type, endpoint[index[i]].val); + printf("select: endpoint %2d %.6f\n", + endpoint[indx[i]].type, + endpoint[indx[i]].val); #endif i = 0; j = nl3 - 1; @@ -1357,30 +1641,30 @@ clock_select(void) while (allow > 0) { allow--; for (n = 0; i <= j; i++) { - n += endpoint[index[i]].type; + n += endpoint[indx[i]].type; if (n < 0) break; - if (endpoint[index[i]].type == 0) + if (endpoint[indx[i]].type == 0) found++; } for (n = 0; i <= j; j--) { - n += endpoint[index[j]].type; + n += endpoint[indx[j]].type; if (n > 0) break; - if (endpoint[index[j]].type == 0) + if (endpoint[indx[j]].type == 0) found++; } if (found > allow) break; - low = endpoint[index[i++]].val; - high = endpoint[index[j--]].val; + low = endpoint[indx[i++]].val; + high = endpoint[indx[j--]].val; } /* - * If no survivors remain at this point, check if the acts or - * local clock drivers have been found. If so, nominate one of - * them as the only survivor. Otherwise, give up and declare us - * unsynchronized. + * If no survivors remain at this point, check if the local + * clock or modem drivers have been found. If so, nominate one + * of them as the only survivor. Otherwise, give up and declare + * us unsynchronized. */ if ((allow << 1) >= nlist) { if (typeacts != 0) { @@ -1392,35 +1676,45 @@ clock_select(void) peer_list[0] = typelocal; nlist = 1; } else { - if (sys_peer != 0) { - report_event(EVNT_PEERSTCHG, - (struct peer *)0); + if (osys_peer != NULL) { + sys_poll = NTP_MINPOLL; NLOG(NLOG_SYNCSTATUS) - msyslog(LOG_INFO, + msyslog(LOG_INFO, "synchronisation lost"); + report_event(EVNT_PEERSTCHG, + (struct peer *)0); } - sys_peer = 0; + sys_survivors = 0; +#ifdef AUTOKEY + resetmanycast(); +#endif /* AUTOKEY */ return; } } #ifdef DEBUG - if (debug > 1) + if (debug > 2) printf("select: low %.6f high %.6f\n", low, high); #endif /* - * Clustering algorithm. Process intersection list to discard - * outlyers. Construct candidate list in cluster order - * determined by the sum of peer synchronization distance plus - * scaled stratum. We must find at least one peer. + * Clustering algorithm. Construct candidate list in order first + * by stratum then by root distance. If we have more than + * MAXCLOCK peers, keep only the best MAXCLOCK of them. Scan the + * list to find falsetickers, who leave the island immediately. + * If a falseticker is not configured, his association raft is + * drowned as well. We must leave at least one peer to collect + * the million bucks. */ j = 0; for (i = 0; i < nlist; i++) { peer = peer_list[i]; - if (nlist > 1 && (low >= peer->offset || - peer->offset >= high)) + if (nlist > 1 && (low >= peer->offset || peer->offset >= + high)) { + if (!(peer->flags & FLAG_CONFIG)) + unpeer(peer); continue; - peer->status = CTL_PST_SEL_CORRECT; + } + peer->status = CTL_PST_SEL_DISTSYSPEER; d = root_distance(peer) + peer->stratum * MAXDISPERSE; if (j >= NTP_MAXCLOCK) { if (d >= synch[j - 1]) @@ -1431,77 +1725,98 @@ clock_select(void) for (k = j; k > 0; k--) { if (d >= synch[k - 1]) break; - synch[k] = synch[k - 1]; peer_list[k] = peer_list[k - 1]; + error[k] = error[k - 1]; + synch[k] = synch[k - 1]; } peer_list[k] = peer; + error[k] = peer->jitter; synch[k] = d; j++; } nlist = j; + for (i = 0; i < nlist; i++) { + peer_list[i]->status = CTL_PST_SEL_SELCAND; #ifdef DEBUG - if (debug > 1) - for (i = 0; i < nlist; i++) + if (debug > 2) printf("select: %s distance %.6f\n", ntoa(&peer_list[i]->srcadr), synch[i]); #endif + } /* - * Now, prune outlyers by root dispersion. Continue as long as - * there are more than NTP_MINCLOCK survivors and the minimum - * select dispersion is greater than the maximum peer - * dispersion. Stop if we are about to discard a prefer peer. + * Now, vote outlyers off the island by select jitter weighted + * by root dispersion. Continue voting as long as there are more + * than NTP_MINCLOCK survivors and the minimum select jitter + * squared is greater than the maximum peer jitter squared. Stop + * if we are about to discard a prefer peer, who of course has + * the immunity idol. */ - for (i = 0; i < nlist; i++) { - peer = peer_list[i]; - error[i] = peer->variance; - if (i < NTP_CANCLOCK) - peer->status = CTL_PST_SEL_SELCAND; - else - peer->status = CTL_PST_SEL_DISTSYSPEER; - } while (1) { - sys_maxd = 0; - d = error[0]; - for (k = i = nlist - 1; i >= 0; i--) { - double sdisp = 0; - - for (j = nlist - 1; j > 0; j--) { - sdisp = NTP_SWEIGHT * (sdisp + - DIFF(peer_list[i]->offset, - peer_list[j]->offset)); + d = 1e9; + e = -1e9; + k = 0; + for (i = 0; i < nlist; i++) { + + if (error[i] < d) + d = error[i]; + f = 0; + if (nlist > 1) { + for (j = 0; j < nlist; j++) + f += DIFF(peer_list[j]->offset, + peer_list[i]->offset); + f /= nlist - 1; } - if (sdisp > sys_maxd) { - sys_maxd = sdisp; + f = max(f, SQUARE(LOGTOD(sys_precision))); + if (f * synch[i] > e) { + sys_selerr = f; + e = f * synch[i]; k = i; } - if (error[i] < d) - d = error[i]; } #ifdef DEBUG - if (debug > 1) + if (debug > 2) printf( "select: survivors %d select %.6f peer %.6f\n", - nlist, SQRT(sys_maxd), SQRT(d)); + k, SQRT(sys_selerr), SQRT(d)); #endif - if (nlist <= NTP_MINCLOCK || sys_maxd <= d || - peer_list[k]->flags & FLAG_PREFER) + if (nlist <= NTP_MINCLOCK || sys_selerr <= d || + peer_list[k]->flags & FLAG_PREFER) break; + if (!(peer_list[k]->flags & FLAG_CONFIG)) + unpeer(peer_list[k]); for (j = k + 1; j < nlist; j++) { peer_list[j - 1] = peer_list[j]; error[j - 1] = error[j]; } nlist--; } + +#ifdef AUTOKEY + /* + * In manycast client mode we may have spooked a sizeable number + * of servers that we don't need. If there are at least + * NTP_MINCLOCK of them, the manycast message will be turned + * off. By the time we get here we nay be ready to prune some of + * them back, but we want to make sure all the candicates have + * had a chance. If they didn't pass the sanity and intersection + * tests, they have already been voted off the island. + */ + if (sys_survivors >= NTP_MINCLOCK && nlist < NTP_MINCLOCK) + resetmanycast(); +#endif /* AUTOKEY */ + sys_survivors = nlist; + #ifdef DEBUG - if (debug > 1) { + if (debug > 2) { for (i = 0; i < nlist; i++) printf( "select: %s offset %.6f, distance %.6f poll %d\n", - ntoa(&peer_list[i]->srcadr), peer_list[i]->offset, - synch[i], peer_list[i]->pollsw); + ntoa(&peer_list[i]->srcadr), + peer_list[i]->offset, synch[i], + peer_list[i]->pollsw); } #endif @@ -1520,27 +1835,30 @@ clock_select(void) * him. We note that the head of the list is at the lowest * stratum and that unsynchronized peers cannot survive this * far. + * + * Note that we go no further, unless the number of survivors is + * a majority of the suckers that have been found reachable and + * no prior source is available. This avoids the transient when + * one of a flock of sources is out to lunch and just happens + * to be the first survivor. */ + if (osys_peer == NULL && 2 * nlist < min(nreach, NTP_MINCLOCK)) + return; leap_consensus = 0; for (i = nlist - 1; i >= 0; i--) { - peer_list[i]->status = CTL_PST_SEL_SYNCCAND; - peer_list[i]->flags |= FLAG_SYSPEER; - poll_update(peer_list[i], peer_list[i]->hpoll); - if (peer_list[i]->stratum == peer_list[0]->stratum) { - leap_consensus |= peer_list[i]->leap; - if (peer_list[i]->refclktype == REFCLK_ATOM_PPS) - typepps = peer_list[i]; - if (peer_list[i] == sys_peer) - typesystem = peer_list[i]; - if (peer_list[i]->flags & FLAG_PREFER) { - typeprefer = peer_list[i]; - if (fabs(typeprefer->offset) < - clock_max) - pps_update = 1; - } - } else { - if (peer_list[i] == sys_peer) - sys_peer = 0; + peer = peer_list[i]; + peer->status = CTL_PST_SEL_SYNCCAND; + peer->flags |= FLAG_SYSPEER; + poll_update(peer, peer->hpoll); + if (peer->stratum == peer_list[0]->stratum) { + leap_consensus |= peer->leap; + if (peer->refclktype == REFCLK_ATOM_PPS && + peer->stratum < STRATUM_UNSPEC) + typepps = peer; + if (peer == osys_peer) + typesystem = peer; + if (peer->flags & FLAG_PREFER) + sys_prefer = peer; } } @@ -1556,38 +1874,45 @@ clock_select(void) * stated. Note that all of these must be at the lowest stratum, * i.e., the stratum of the head of the survivor list. */ - osys_peer = sys_peer; - if (typeprefer && (typeprefer->refclktype == REFCLK_LOCALCLOCK - || typeprefer->sstclktype == CTL_SST_TS_TELEPHONE || - !typepps)) { - sys_peer = typeprefer; + if (sys_prefer) + sw = sys_prefer->refclktype == REFCLK_LOCALCLOCK || + sys_prefer->sstclktype == CTL_SST_TS_TELEPHONE || + !typepps; + else + sw = 0; + if (sw) { + sys_peer = sys_prefer; sys_peer->status = CTL_PST_SEL_SYSPEER; sys_offset = sys_peer->offset; - sys_epsil = sys_peer->variance; + sys_syserr = sys_peer->jitter; #ifdef DEBUG if (debug > 1) printf("select: prefer offset %.6f\n", sys_offset); #endif - } else if (typepps && pps_update) { + } else if (typepps) { sys_peer = typepps; sys_peer->status = CTL_PST_SEL_PPS; sys_offset = sys_peer->offset; - sys_epsil = sys_peer->variance; + sys_syserr = sys_peer->jitter; if (!pps_control) - NLOG(NLOG_SYSEVENT) /* conditional syslog */ - msyslog(LOG_INFO, "pps sync enabled"); + NLOG(NLOG_SYSEVENT) + msyslog(LOG_INFO, + "pps sync enabled"); pps_control = current_time; #ifdef DEBUG if (debug > 1) - printf("select: pps offset %.6f\n", sys_offset); + printf("select: pps offset %.6f\n", + sys_offset); #endif } else { - if (!typesystem) + if (typesystem) + sys_peer = osys_peer; + else sys_peer = peer_list[0]; sys_peer->status = CTL_PST_SEL_SYSPEER; sys_offset = clock_combine(peer_list, nlist); - sys_epsil = sys_peer->variance + sys_maxd; + sys_syserr = sys_peer->jitter + sys_selerr; #ifdef DEBUG if (debug > 1) printf("select: combine offset %.6f\n", @@ -1627,10 +1952,14 @@ root_distance( struct peer *peer ) { - return ((fabs(peer->delay) + peer->rootdelay) / 2 + - peer->rootdispersion + peer->disp + - SQRT(peer->variance) + CLOCK_PHI * (current_time - - peer->update)); + /* + * Careful squeak here. The value returned must be greater than + * zero blamed on the peer jitter, which must be at least the + * square of sys_precision. + */ + return ((peer->rootdelay + peer->delay) / 2 + + peer->rootdispersion + peer->disp + clock_phi * + (current_time - peer->update) + SQRT(peer->jitter)); } /* @@ -1641,279 +1970,518 @@ peer_xmit( struct peer *peer /* peer structure pointer */ ) { - struct pkt xpkt; - int find_rtt = (peer->cast_flags & MDF_MCAST) && - peer->hmode != MODE_BROADCAST; - int sendlen; + struct pkt xpkt; /* transmit packet */ + int sendlen, authlen; + keyid_t xkeyid; /* transmit key ID */ + l_fp xmt_tx; /* - * Initialize protocol fields. + * Initialize transmit packet header fields. */ - xpkt.li_vn_mode = PKT_LI_VN_MODE(sys_leap, - peer->version, peer->hmode); + xpkt.li_vn_mode = PKT_LI_VN_MODE(sys_leap, peer->version, + peer->hmode); xpkt.stratum = STRATUM_TO_PKT(sys_stratum); xpkt.ppoll = peer->hpoll; xpkt.precision = sys_precision; xpkt.rootdelay = HTONS_FP(DTOFP(sys_rootdelay)); - xpkt.rootdispersion = HTONS_FP(DTOUFP(sys_rootdispersion + - LOGTOD(sys_precision))); + xpkt.rootdispersion = HTONS_FP(DTOUFP(sys_rootdispersion)); xpkt.refid = sys_refid; HTONL_FP(&sys_reftime, &xpkt.reftime); HTONL_FP(&peer->org, &xpkt.org); HTONL_FP(&peer->rec, &xpkt.rec); /* - * Authenticate the packet if enabled and either configured or - * the previous packet was authenticated. If for some reason the - * key associated with the key identifier is not in the key - * cache, then honk key zero. + * If the received packet contains a MAC, the transmitted packet + * is authenticated and contains a MAC. If not, the transmitted + * packet is not authenticated. + * + * In the current I/O semantics the default interface is set + * until after receiving a packet and setting the right + * interface. So, the first packet goes out unauthenticated. + * That's why the really icky test next is here. */ sendlen = LEN_PKT_NOMAC; - if (peer->flags & FLAG_AUTHENABLE) { - u_long xkeyid; - l_fp xmt_tx; + if (!(peer->flags & FLAG_AUTHENABLE)) { + get_systime(&peer->xmt); + HTONL_FP(&peer->xmt, &xpkt.xmt); + sendpkt(&peer->srcadr, peer->dstadr, peer->ttl, &xpkt, + sendlen); + peer->sent++; +#ifdef DEBUG + if (debug) + printf("transmit: at %ld %s->%s mode %d\n", + current_time, ntoa(&peer->dstadr->sin), + ntoa(&peer->srcadr), peer->hmode); +#endif + return; + } + + /* + * The received packet contains a MAC, so the transmitted packet + * must be authenticated. If autokey is enabled, fuss with the + * various modes; otherwise, private key cryptography is used. + */ +#ifdef AUTOKEY + if ((peer->flags & FLAG_SKEY)) { + u_int cmmd; /* - * Transmit encrypted packet compensated for the - * encryption delay. + * The Public Key Dance (PKD): Cryptographic credentials + * are contained in extension fields, each including a + * 4-octet length/code word followed by a 4-octet + * association ID and optional additional data. Optional + * data includes a 4-octet data length field followed by + * the data itself. Request messages are sent from a + * configured association; response messages can be sent + * from a configured association or can take the fast + * path without ever matching an association. Response + * messages have the same code as the request, but have + * a response bit and possibly an error bit set. In this + * implementation, a message may contain no more than + * one command and no more than one response. + * + * Cryptographic session keys include both a public and + * a private componet. Request and response messages + * using extension fields are always sent with the + * private component set to zero. Packets without + * extension fields indlude the private component when + * the session key is generated. */ -#ifdef MD5 - if (peer->flags & FLAG_SKEY) { - + while (1) { + /* - * In autokey mode, allocate and initialize a - * key list if not already done. Then, use the - * list in inverse order, discarding keys once - * used. Keep the latest key around until the - * next one, so clients can use client/server - * packets to compute propagation delay. Note we - * have to wait until the receive side of the - * socket is bound and the server address - * confirmed. + * Allocate and initialize a keylist if not + * already done. Then, use the list in inverse + * order, discarding keys once used. Keep the + * latest key around until the next one, so + * clients can use client/server packets to + * compute propagation delay. + * + * Note that once a key is used from the list, + * it is retained in the key cache until the + * next key is used. This is to allow a client + * to retrieve the encrypted session key + * identifier to verify authenticity. + * + * If for some reason a key is no longer in the + * key cache, a birthday has happened and the + * pseudo-random sequence is probably broken. In + * that case, purge the keylist and regenerate + * it. */ - if (ntohl(peer->dstadr->sin.sin_addr.s_addr) == - 0 && - ntohl(peer->dstadr->bcast.sin_addr.s_addr) == 0) - peer->keyid = 0; - else { - if (peer->keylist == 0) { - make_keylist(peer); - } else { - authtrust(peer->keylist[peer->keynumber], 0); - if (peer->keynumber == 0) - make_keylist(peer); - else { - peer->keynumber--; - xkeyid = peer->keylist[peer->keynumber]; - if (!authistrusted(xkeyid)) - make_keylist(peer); - } - } - peer->keyid = peer->keylist[peer->keynumber]; - xpkt.keyid1 = htonl(2 * sizeof(u_int32)); - xpkt.keyid2 = htonl(sys_private); - sendlen += 2 * sizeof(u_int32); - } + if (peer->keynumber == 0) + make_keylist(peer, peer->dstadr); + else + peer->keynumber--; + xkeyid = peer->keylist[peer->keynumber]; + if (authistrusted(xkeyid)) + break; + else + key_expire(peer); } -#endif /* MD5 */ - xkeyid = peer->keyid; - get_systime(&peer->xmt); - L_ADD(&peer->xmt, &sys_authdelay); - HTONL_FP(&peer->xmt, &xpkt.xmt); - sendlen += authencrypt(xkeyid, (u_int32 *)&xpkt, - sendlen); - get_systime(&xmt_tx); - sendpkt(&peer->srcadr, find_rtt ? any_interface : - peer->dstadr, ((peer->cast_flags & MDF_MCAST) && - !find_rtt) ? ((peer->cast_flags & MDF_ACAST) ? -7 : - peer->ttl) : -7, &xpkt, sendlen); + peer->keyid = xkeyid; + switch (peer->hmode) { /* - * Calculate the encryption delay. Keep the minimum over - * the latest two samples. + * In broadcast mode the autokey values are required. + * Send them when a new keylist is generated; otherwise, + * send the association ID so the client can request + * them at other times. */ - L_SUB(&xmt_tx, &peer->xmt); - L_ADD(&xmt_tx, &sys_authdelay); - sys_authdly[1] = sys_authdly[0]; - sys_authdly[0] = xmt_tx.l_uf; - if (sys_authdly[0] < sys_authdly[1]) - sys_authdelay.l_uf = sys_authdly[0]; - else - sys_authdelay.l_uf = sys_authdly[1]; - peer->sent++; -#ifdef DEBUG - if (debug) - printf( - "transmit: at %ld to %s mode %d keyid %08lx index %d\n", - current_time, ntoa(&peer->srcadr), - peer->hmode, xkeyid, peer->keynumber); -#endif - } else { + case MODE_BROADCAST: + if (peer->flags & FLAG_ASSOC) + cmmd = CRYPTO_AUTO | CRYPTO_RESP; + else + cmmd = CRYPTO_ASSOC | CRYPTO_RESP; + sendlen += crypto_xmit((u_int32 *)&xpkt, + sendlen, cmmd, 0, peer->associd); + break; + /* - * Transmit non-authenticated packet. + * In symmetric modes the public key, leapsecond table, + * agreement parameters and autokey values are required. + * + * 1. If a response is pending, always send it first. + * + * 2. Don't send anything except a public-key request + * until the public key has been stored. + * + * 3. Once the public key has been stored, don't send + * anything except an agreement parameter request + * until the agreement parameters have been stored. + * + * 4. Once the argeement parameters have been stored, + * don't send anything except a public value request + * until the agreed key has been stored. + * + * 5. When the agreed key has been stored and the key + * list is regenerated, send the autokey values + * gratis unless they have already been sent. */ - get_systime(&(peer->xmt)); - HTONL_FP(&peer->xmt, &xpkt.xmt); - sendpkt(&(peer->srcadr), find_rtt ? any_interface : - peer->dstadr, ((peer->cast_flags & MDF_MCAST) && - !find_rtt) ? ((peer->cast_flags & MDF_ACAST) ? -7 : - peer->ttl) : -8, &xpkt, sendlen); - peer->sent++; + case MODE_ACTIVE: + case MODE_PASSIVE: +#ifdef PUBKEY + if (peer->cmmd != 0) + sendlen += crypto_xmit((u_int32 *)&xpkt, + sendlen, (peer->cmmd >> 16) | + CRYPTO_RESP, peer->hcookie, + peer->associd); + if (!peer->crypto) + sendlen += crypto_xmit((u_int32 *)&xpkt, + sendlen, CRYPTO_ASSOC, + peer->hcookie, peer->assoc); + else if (!crypto_flags && + peer->pcookie.tstamp == 0 && sys_leap != + LEAP_NOTINSYNC) + sendlen += crypto_xmit((u_int32 *)&xpkt, + sendlen, CRYPTO_PRIV, peer->hcookie, + peer->assoc); + else if (crypto_flags && peer->pubkey.ptr == + NULL) + sendlen += crypto_xmit((u_int32 *)&xpkt, + sendlen, CRYPTO_NAME, peer->hcookie, + peer->assoc); + else if (peer->crypto & CRYPTO_FLAG_CERT) + sendlen += crypto_xmit((u_int32 *)&xpkt, + sendlen, CRYPTO_CERT, peer->hcookie, + peer->assoc); + else if (crypto_flags && peer->crypto & + CRYPTO_FLAG_DH && sys_leap != + LEAP_NOTINSYNC) + sendlen += crypto_xmit((u_int32 *)&xpkt, + sendlen, CRYPTO_DHPAR, + peer->hcookie, peer->assoc); + else if (crypto_flags && peer->pcookie.tstamp == + 0 && sys_leap != LEAP_NOTINSYNC) + sendlen += crypto_xmit((u_int32 *)&xpkt, + sendlen, CRYPTO_DH, peer->hcookie, + peer->assoc); +#else + if (peer->cmmd != 0) + sendlen += crypto_xmit((u_int32 *)&xpkt, + sendlen, (peer->cmmd >> 16) | + CRYPTO_RESP, peer->hcookie, + peer->associd); + if (peer->pcookie.tstamp == 0 && sys_leap != + LEAP_NOTINSYNC) + sendlen += crypto_xmit((u_int32 *)&xpkt, + sendlen, CRYPTO_PRIV, peer->hcookie, + peer->assoc); +#endif /* PUBKEY */ + else if (!(peer->flags & FLAG_AUTOKEY)) + sendlen += crypto_xmit((u_int32 *)&xpkt, + sendlen, CRYPTO_AUTO, peer->hcookie, + peer->assoc); + else if ((peer->flags & FLAG_ASSOC) && + (peer->cmmd >> 16) != CRYPTO_AUTO) + sendlen += crypto_xmit((u_int32 *)&xpkt, + sendlen, CRYPTO_AUTO | CRYPTO_RESP, + peer->hcookie, peer->associd); +#ifdef PUBKEY + else if (peer->crypto & CRYPTO_FLAG_TAI) + sendlen += crypto_xmit((u_int32 *)&xpkt, + sendlen, CRYPTO_TAI, peer->hcookie, + peer->assoc); +#endif /* PUBKEY */ + peer->cmmd = 0; + break; + + /* + * In client mode, the public key, host cookie and + * autokey values are required. In broadcast client + * mode, these values must be acquired during the + * client/server exchange to avoid having to wait until + * the next key list regeneration. Otherwise, the poor + * dude may die a lingering death until becoming + * unreachable and attempting rebirth. Note that we ask + * for the cookie at each key list regeneration anyway. + */ + case MODE_CLIENT: + if (peer->cmmd != 0) + sendlen += crypto_xmit((u_int32 *)&xpkt, + sendlen, (peer->cmmd >> 16) | + CRYPTO_RESP, peer->hcookie, + peer->associd); + if (!peer->crypto) + sendlen += crypto_xmit((u_int32 *)&xpkt, + sendlen, CRYPTO_ASSOC, + peer->hcookie, peer->assoc); +#ifdef PUBKEY + else if (crypto_flags && peer->pubkey.ptr == + NULL) + sendlen += crypto_xmit((u_int32 *)&xpkt, + sendlen, CRYPTO_NAME, peer->hcookie, + peer->assoc); + else if (peer->crypto & CRYPTO_FLAG_CERT) + sendlen += crypto_xmit((u_int32 *)&xpkt, + sendlen, CRYPTO_CERT, peer->hcookie, + peer->assoc); +#endif /* PUBKEY */ + else if (peer->pcookie.tstamp == 0) + sendlen += crypto_xmit((u_int32 *)&xpkt, + sendlen, CRYPTO_PRIV, peer->hcookie, + peer->assoc); + else if (!(peer->flags & FLAG_AUTOKEY) && + (peer->cast_flags & MDF_BCLNT)) + sendlen += crypto_xmit((u_int32 *)&xpkt, + sendlen, CRYPTO_AUTO, peer->hcookie, + peer->assoc); +#ifdef PUBKEY + else if (peer->crypto & CRYPTO_FLAG_TAI) + sendlen += crypto_xmit((u_int32 *)&xpkt, + sendlen, CRYPTO_TAI, peer->hcookie, + peer->assoc); +#endif /* PUBKEY */ + peer->cmmd = 0; + break; + } + + /* + * If extension fields are present, we must use a + * private value of zero and force min poll interval. + * Most intricate. + */ + if (sendlen > LEN_PKT_NOMAC) + session_key(&peer->dstadr->sin, &peer->srcadr, + xkeyid, 0, 2); + } +#endif /* AUTOKEY */ + xkeyid = peer->keyid; + get_systime(&peer->xmt); + L_ADD(&peer->xmt, &sys_authdelay); + HTONL_FP(&peer->xmt, &xpkt.xmt); + authlen = authencrypt(xkeyid, (u_int32 *)&xpkt, sendlen); + if (authlen == 0) { + msyslog(LOG_NOTICE, + "transmit: no encryption key found"); + peer->flash |= TEST4 | TEST5; + return; + } + sendlen += authlen; +#ifdef AUTOKEY + if (xkeyid > NTP_MAXKEY) + authtrust(xkeyid, 0); +#endif /* AUTOKEY */ + get_systime(&xmt_tx); + if (sendlen > sizeof(xpkt)) { + msyslog(LOG_ERR, "buffer overflow %u", sendlen); + exit(-1); + } + sendpkt(&peer->srcadr, peer->dstadr, peer->ttl, &xpkt, sendlen); + + /* + * Calculate the encryption delay. Keep the minimum over + * the latest two samples. + */ + L_SUB(&xmt_tx, &peer->xmt); + L_ADD(&xmt_tx, &sys_authdelay); + sys_authdly[1] = sys_authdly[0]; + sys_authdly[0] = xmt_tx.l_uf; + if (sys_authdly[0] < sys_authdly[1]) + sys_authdelay.l_uf = sys_authdly[0]; + else + sys_authdelay.l_uf = sys_authdly[1]; + peer->sent++; +#ifdef AUTOKEY #ifdef DEBUG - if (debug) - printf("transmit: at %ld to %s mode %d\n", - current_time, ntoa(&peer->srcadr), - peer->hmode); + if (debug) + printf( + "transmit: at %ld %s->%s mode %d keyid %08x len %d mac %d index %d\n", + current_time, ntoa(&peer->dstadr->sin), + ntoa(&peer->srcadr), peer->hmode, xkeyid, sendlen, + authlen, peer->keynumber); #endif - } +#else +#ifdef DEBUG + if (debug) + printf( + "transmit: at %ld %s->%s mode %d keyid %08x len %d mac %d\n", + current_time, ntoa(&peer->dstadr->sin), + ntoa(&peer->srcadr), peer->hmode, xkeyid, sendlen, + authlen); +#endif +#endif /* AUTOKEY */ } + /* - * fast_xmit - Send packet for nonpersistent association. + * fast_xmit - Send packet for nonpersistent association. Note that + * neither the source or destination can be a broadcast address. */ static void fast_xmit( struct recvbuf *rbufp, /* receive packet pointer */ int xmode, /* transmit mode */ - u_long xkeyid /* transmit key ID */ + keyid_t xkeyid, /* transmit key ID */ + int mask /* restrict mask */ ) { - struct pkt xpkt; - struct pkt *rpkt; - int sendlen; - l_fp xmt_ts; + struct pkt xpkt; /* transmit packet structure */ + struct pkt *rpkt; /* receive packet structure */ + l_fp xmt_ts; /* transmit timestamp */ + l_fp xmt_tx; /* transmit timestamp after authent */ + int sendlen, authlen; /* - * Initialize transmit packet header fields in the receive - * buffer provided. We leave some fields intact as received. + * Initialize transmit packet header fields from the receive + * buffer provided. We leave some fields intact as received. If + * the gazinta was from a multicast address, the gazouta must go + * out another way. */ rpkt = &rbufp->recv_pkt; - xpkt.li_vn_mode = PKT_LI_VN_MODE(sys_leap, - PKT_VERSION(rpkt->li_vn_mode), xmode); - xpkt.stratum = STRATUM_TO_PKT(sys_stratum); + if (rbufp->dstadr->flags & INT_MULTICAST) + rbufp->dstadr = findinterface(&rbufp->recv_srcadr); + + /* + * If the caller is restricted, return a kiss-of-death packet; + * otherwise, smooch politely. + */ + if (mask & (RES_DONTSERVE | RES_LIMITED)) { + if (!(mask & RES_DEMOBILIZE)) { + return; + } else { + xpkt.li_vn_mode = + PKT_LI_VN_MODE(LEAP_NOTINSYNC, + PKT_VERSION(rpkt->li_vn_mode), xmode); + xpkt.stratum = STRATUM_UNSPEC; + memcpy(&xpkt.refid, "DENY", 4); + } + } else { + xpkt.li_vn_mode = PKT_LI_VN_MODE(sys_leap, + PKT_VERSION(rpkt->li_vn_mode), xmode); + xpkt.stratum = STRATUM_TO_PKT(sys_stratum); + xpkt.refid = sys_refid; + } xpkt.ppoll = rpkt->ppoll; xpkt.precision = sys_precision; xpkt.rootdelay = HTONS_FP(DTOFP(sys_rootdelay)); - xpkt.rootdispersion = HTONS_FP(DTOUFP(sys_rootdispersion + - LOGTOD(sys_precision))); - xpkt.refid = sys_refid; + xpkt.rootdispersion = + HTONS_FP(DTOUFP(sys_rootdispersion)); HTONL_FP(&sys_reftime, &xpkt.reftime); xpkt.org = rpkt->xmt; HTONL_FP(&rbufp->recv_time, &xpkt.rec); - sendlen = LEN_PKT_NOMAC; - if (rbufp->recv_length > sendlen) { - l_fp xmt_tx; - /* - * Transmit encrypted packet compensated for the - * encryption delay. - */ - if (xkeyid > NTP_MAXKEY) { - xpkt.keyid1 = htonl(2 * sizeof(u_int32)); - xpkt.keyid2 = htonl(sys_private); - sendlen += 2 * sizeof(u_int32); - } + /* + * If the received packet contains a MAC, the transmitted packet + * is authenticated and contains a MAC. If not, the transmitted + * packet is not authenticated. + */ + sendlen = LEN_PKT_NOMAC; + if (rbufp->recv_length == sendlen) { get_systime(&xmt_ts); - L_ADD(&xmt_ts, &sys_authdelay); HTONL_FP(&xmt_ts, &xpkt.xmt); - sendlen += authencrypt(xkeyid, (u_int32 *)&xpkt, + sendpkt(&rbufp->recv_srcadr, rbufp->dstadr, 0, &xpkt, sendlen); - get_systime(&xmt_tx); - sendpkt(&rbufp->recv_srcadr, rbufp->dstadr, -9, &xpkt, - sendlen); - - /* - * Calculate the encryption delay. Keep the minimum over - * the latest two samples. - */ - L_SUB(&xmt_tx, &xmt_ts); - L_ADD(&xmt_tx, &sys_authdelay); - sys_authdly[1] = sys_authdly[0]; - sys_authdly[0] = xmt_tx.l_uf; - if (sys_authdly[0] < sys_authdly[1]) - sys_authdelay.l_uf = sys_authdly[0]; - else - sys_authdelay.l_uf = sys_authdly[1]; #ifdef DEBUG if (debug) - printf( - "transmit: at %ld to %s mode %d keyid %08lx\n", - current_time, ntoa(&rbufp->recv_srcadr), - xmode, xkeyid); + printf("transmit: at %ld %s->%s mode %d\n", + current_time, ntoa(&rbufp->dstadr->sin), + ntoa(&rbufp->recv_srcadr), xmode); #endif - } else { + return; + } + + /* + * The received packet contains a MAC, so the transmitted packet + * must be authenticated. For private-key cryptography, use the + * predefined private keys to generate the cryptosum. For + * autokey cryptography, use the server private value to + * generate the cookie, which is unique for every source- + * destination-key ID combination. + */ +#ifdef AUTOKEY + if (xkeyid > NTP_MAXKEY) { + keyid_t cookie; + u_int code, associd; /* - * Transmit non-authenticated packet. + * The only way to get here is a reply to a legitimate + * client request message, so the mode must be + * MODE_SERVER. If an extension field is present, there + * can be only one and that must be a command. Do what + * needs, but with private value of zero so the poor + * jerk can decode it. If no extension field is present, + * use the cookie to generate the session key. */ - get_systime(&xmt_ts); - HTONL_FP(&xmt_ts, &xpkt.xmt); - sendpkt(&rbufp->recv_srcadr, rbufp->dstadr, -10, &xpkt, - sendlen); + code = (htonl(rpkt->exten[0]) >> 16) | CRYPTO_RESP; + cookie = session_key(&rbufp->recv_srcadr, + &rbufp->dstadr->sin, 0, sys_private, 0); + associd = htonl(rpkt->exten[1]); + if (rbufp->recv_length >= sendlen + MAX_MAC_LEN + 2 * + sizeof(u_int32)) { + session_key(&rbufp->dstadr->sin, + &rbufp->recv_srcadr, xkeyid, 0, 2); + sendlen += crypto_xmit((u_int32 *)&xpkt, + sendlen, code, cookie, associd); + } else { + session_key(&rbufp->dstadr->sin, + &rbufp->recv_srcadr, xkeyid, cookie, 2); + } + } +#endif /* AUTOKEY */ + get_systime(&xmt_ts); + L_ADD(&xmt_ts, &sys_authdelay); + HTONL_FP(&xmt_ts, &xpkt.xmt); + authlen = authencrypt(xkeyid, (u_int32 *)&xpkt, sendlen); + sendlen += authlen; +#ifdef AUTOKEY + if (xkeyid > NTP_MAXKEY) + authtrust(xkeyid, 0); +#endif /* AUTOKEY */ + get_systime(&xmt_tx); + if (sendlen > sizeof(xpkt)) { + msyslog(LOG_ERR, "buffer overflow %u", sendlen); + exit(-1); + } + sendpkt(&rbufp->recv_srcadr, rbufp->dstadr, 0, &xpkt, sendlen); + + /* + * Calculate the encryption delay. Keep the minimum over the + * latest two samples. + */ + L_SUB(&xmt_tx, &xmt_ts); + L_ADD(&xmt_tx, &sys_authdelay); + sys_authdly[1] = sys_authdly[0]; + sys_authdly[0] = xmt_tx.l_uf; + if (sys_authdly[0] < sys_authdly[1]) + sys_authdelay.l_uf = sys_authdly[0]; + else + sys_authdelay.l_uf = sys_authdly[1]; #ifdef DEBUG - if (debug) - printf("transmit: at %ld to %s mode %d\n", - current_time, ntoa(&rbufp->recv_srcadr), - xmode); + if (debug) + printf( + "transmit: at %ld %s->%s mode %d keyid %08x len %d mac %d\n", + current_time, ntoa(&rbufp->dstadr->sin), + ntoa(&rbufp->recv_srcadr), xmode, xkeyid, sendlen, + authlen); #endif - } } -#ifdef MD5 + +#ifdef AUTOKEY /* - * Compute key list + * key_expire - purge the key list */ -static void -make_keylist( - struct peer *peer +void +key_expire( + struct peer *peer /* peer structure pointer */ ) { int i; - u_long keyid; - u_long ltemp; - /* - * Allocate the key list if necessary. - */ - if (peer->keylist == 0) - peer->keylist = (u_long *)emalloc(sizeof(u_long) * - NTP_MAXSESSION); - - /* - * Generate an initial key ID which is unique and greater than - * NTP_MAXKEY. - */ - while (1) { - keyid = (u_long)RANDOM & 0xffffffff; - if (keyid <= NTP_MAXKEY) - continue; - if (authhavekey(keyid)) - continue; - break; - } - - /* - * Generate up to NTP_MAXSESSION session keys. Stop if the - * next one would not be unique or not a session key ID or if - * it would expire before the next poll. - */ - ltemp = sys_automax; - for (i = 0; i < NTP_MAXSESSION; i++) { - peer->keylist[i] = keyid; - peer->keynumber = i; - keyid = session_key( - ntohl(peer->dstadr->sin.sin_addr.s_addr), - (peer->hmode == MODE_BROADCAST || (peer->flags & - FLAG_MCAST2)) ? - ntohl(peer->dstadr->bcast.sin_addr.s_addr): - ntohl(peer->srcadr.sin_addr.s_addr), keyid, ltemp); - ltemp -= 1 << peer->hpoll; - if (auth_havekey(keyid) || keyid <= NTP_MAXKEY || - ltemp <= (1 << (peer->hpoll + 1))) - break; + if (peer->keylist != NULL) { + for (i = 0; i <= peer->keynumber; i++) + authtrust(peer->keylist[i], 0); + free(peer->keylist); + peer->keylist = NULL; } + peer->keynumber = peer->sndauto.seq = 0; +#ifdef DEBUG + if (debug) + printf("key_expire: at %lu\n", current_time); +#endif } -#endif /* MD5 */ +#endif /* AUTOKEY */ /* * Find the precision of this particular machine @@ -2033,19 +2601,17 @@ init_proto(void) sys_leap = LEAP_NOTINSYNC; sys_stratum = STRATUM_UNSPEC; sys_precision = (s_char)default_get_precision(); + sys_jitter = LOGTOD(sys_precision); sys_rootdelay = 0; sys_rootdispersion = 0; sys_refid = 0; L_CLR(&sys_reftime); - sys_peer = 0; + sys_peer = NULL; + sys_survivors = 0; get_systime(&dummy); sys_bclient = 0; sys_bdelay = DEFBROADDELAY; -#if defined(DES) || defined(MD5) sys_authenticate = 1; -#else - sys_authenticate = 0; -#endif L_CLR(&sys_authdelay); sys_authdly[0] = sys_authdly[1] = 0; sys_stattime = 0; @@ -2057,7 +2623,9 @@ init_proto(void) sys_processed = 0; sys_badauth = 0; sys_manycastserver = 0; +#ifdef AUTOKEY sys_automax = 1 << NTP_AUTOMAX; +#endif /* AUTOKEY */ /* * Default these to enable @@ -2066,11 +2634,12 @@ init_proto(void) #ifndef KERNEL_FLL_BUG kern_enable = 1; #endif - msyslog(LOG_DEBUG, "kern_enable is %d", kern_enable); + pps_enable = 0; stats_control = 1; /* - * Some system clocks should only be adjusted in 10ms increments. + * Some system clocks should only be adjusted in 10ms + * increments. */ #if defined RELIANTUNIX_CLOCK systime_10ms_ticks = 1; /* Reliant UNIX */ @@ -2176,6 +2745,24 @@ proto_config( sys_authenticate = (int)value; break; + case PROTO_PPS: + + /* + * Turn on/off PPS discipline + */ + pps_enable = (int)value; + break; + +#ifdef REFCLOCK + case PROTO_CAL: + + /* + * Turn on/off refclock calibrate + */ + cal_enable = (int)value; + break; +#endif + default: /* -- cgit v1.1