1/* 2 * ntp_proto.c - NTP version 4 protocol machinery 3 * |
4 * ATTENTION: Get approval from Dave Mills on all changes to this file! 5 * |
6 */ 7#ifdef HAVE_CONFIG_H 8#include <config.h> 9#endif 10 11#include "ntpd.h" 12#include "ntp_stdlib.h" 13#include "ntp_unixtime.h" 14#include "ntp_control.h" 15#include "ntp_string.h" |
16 17#include <stdio.h> 18 19#if defined(VMS) && defined(VMS_LOCALUNIT) /*wjm*/ 20#include "ntp_refclock.h" 21#endif 22 23#if defined(__FreeBSD__) && __FreeBSD__ >= 3 --- 5 unchanged lines hidden (view full) --- 29 * specification. 30 */ 31u_char sys_leap; /* system leap indicator */ 32u_char sys_stratum; /* stratum of system */ 33s_char sys_precision; /* local clock precision */ 34double sys_rootdelay; /* roundtrip delay to primary source */ 35double sys_rootdispersion; /* dispersion to primary source */ 36u_int32 sys_refid; /* reference source for local clock */ |
37u_int32 sys_peer_refid; /* hashed refid of our current peer */ |
38static double sys_offset; /* current local clock offset */ 39l_fp sys_reftime; /* time we were last updated */ |
40struct peer *sys_peer; /* our current peer */ |
41struct peer *sys_prefer; /* our cherished peer */ |
42int sys_kod; /* kod credit */ 43int sys_kod_rate = 2; /* max kod packets per second */ 44#ifdef OPENSSL |
45u_long sys_automax; /* maximum session key lifetime */ |
46#endif /* OPENSSL */ |
47 48/* 49 * Nonspecified system state variables. 50 */ |
51int sys_bclient; /* broadcast client enable */ 52double sys_bdelay; /* broadcast client default delay */ 53int sys_calldelay; /* modem callup delay (s) */ |
54int sys_authenticate; /* requre authentication for config */ 55l_fp sys_authdelay; /* authentication delay */ |
56static u_long sys_authdly[2]; /* authentication delay shift reg */ |
57static u_char leap_consensus; /* consensus of survivor leap bits */ |
58static double sys_selerr; /* select error (squares) */ |
59static double sys_syserr; /* system error (squares) */ 60keyid_t sys_private; /* private value for session seed */ 61int sys_manycastserver; /* respond to manycast client pkts */ |
62int peer_ntpdate; /* active peers in ntpdate mode */ |
63int sys_survivors; /* truest of the truechimers */ 64#ifdef OPENSSL |
65char *sys_hostname; /* gethostname() name */ |
66#endif /* OPENSSL */ |
67 68/* |
69 * TOS and multicast mapping stuff 70 */ 71int sys_floor = 1; /* cluster stratum floor */ 72int sys_ceiling = STRATUM_UNSPEC; /* cluster stratum ceiling*/ 73int sys_minsane = 1; /* minimum candidates */ 74int sys_minclock = NTP_MINCLOCK; /* minimum survivors */ 75int sys_cohort = 0; /* cohort switch */ 76int sys_ttlmax; /* max ttl mapping vector index */ 77u_char sys_ttl[MAX_TTL]; /* ttl mapping vector */ 78 79/* |
80 * Statistics counters 81 */ |
82u_long sys_stattime; /* time since reset */ 83u_long sys_received; /* packets received */ |
84u_long sys_processed; /* packets processed */ |
85u_long sys_newversionpkt; /* current version */ 86u_long sys_oldversionpkt; /* recent version */ 87u_long sys_unknownversion; /* invalid version */ 88u_long sys_restricted; /* access denied */ 89u_long sys_badlength; /* bad length or format */ 90u_long sys_badauth; /* bad authentication */ 91u_long sys_limitrejected; /* rate exceeded */ |
92 93static double root_distance P((struct peer *)); 94static double clock_combine P((struct peer **, int)); 95static void peer_xmit P((struct peer *)); 96static void fast_xmit P((struct recvbuf *, int, keyid_t, int)); 97static void clock_update P((void)); 98int default_get_precision P((void)); |
99static int peer_unfit P((struct peer *)); |
100 |
101/* 102 * transmit - Transmit Procedure. See Section 3.4.2 of the 103 * specification. 104 */ 105void 106transmit( 107 struct peer *peer /* peer structure pointer */ 108 ) 109{ |
110 int hpoll; |
111 |
112 113 /* 114 * The polling state machine. There are two kinds of machines, 115 * those that never expect a reply (broadcast and manycast 116 * server modes) and those that do (all other modes). The dance 117 * is intricate... 118 */ |
119 hpoll = peer->hpoll; |
120 if (peer->cast_flags & (MDF_BCAST | MDF_MCAST)) { |
121 122 /* |
123 * In broadcast mode the poll interval is fixed 124 * at minpoll. |
125 */ |
126 hpoll = peer->minpoll; 127 } else if (peer->cast_flags & MDF_ACAST) { |
128 |
129 /* 130 * In manycast mode we start with the minpoll interval 131 * and ttl. However, the actual poll interval is eight 132 * times the nominal poll interval shown here. If fewer 133 * than sys_minclock servers are found, the ttl is 134 * increased by one and we try again. If this continues 135 * to the max ttl, the poll interval is bumped by one 136 * and we try again. If at least sys_minclock servers 137 * are found, the poll interval increases with the 138 * system poll interval to the max and we continue 139 * indefinately. However, about once per day when the 140 * agreement parameters are refreshed, the manycast 141 * clients are reset and we start from the beginning. 142 * This is to catch and clamp the ttl to the lowest 143 * practical value and avoid knocking on spurious doors. 144 */ 145 if (sys_survivors < sys_minclock && peer->ttl < 146 sys_ttlmax) 147 peer->ttl++; 148 hpoll = sys_poll; 149 } else { |
150 |
151 /* 152 * For associations expecting a reply, the watchdog 153 * counter is bumped by one if the peer has not been 154 * heard since the previous poll. If the counter reaches 155 * the max, the poll interval is doubled and the peer is 156 * demobilized if not configured. 157 */ 158 peer->unreach++; 159 if (peer->unreach >= NTP_UNREACH) { 160 hpoll++; 161 if (peer->flags & FLAG_CONFIG) { |
162 |
163 /* 164 * If nothing is likely to change in 165 * future, flash the access denied bit 166 * so we won't bother the dude again. 167 */ 168 if (memcmp((char *)&peer->refid, 169 "DENY", 4) == 0 || 170 memcmp((char *)&peer->refid, 171 "CRYP", 4) == 0) 172 peer->flash |= TEST4; 173 } else { |
174 unpeer(peer); |
175 return; |
176 } 177 } |
178 if (peer->burst == 0) { 179 u_char oreach; |
180 |
181 oreach = peer->reach; 182 peer->reach <<= 1; 183 peer->hyst *= HYST_TC; 184 if (peer->reach == 0) { 185 186 /* 187 * If this association has become 188 * unreachable, clear it and raise a 189 * trap. 190 */ 191 if (oreach != 0) { 192 report_event(EVNT_UNREACH, 193 peer); 194 peer->timereachable = 195 current_time; 196 if (peer->flags & FLAG_CONFIG) { 197 peer_clear(peer, 198 "INIT"); 199 } else { 200 unpeer(peer); 201 return; 202 } 203 } 204 if (peer->flags & FLAG_IBURST) 205 peer->burst = NTP_BURST; 206 } else { 207 /* 208 * Here the peer is reachable. If it has 209 * not been heard for three consecutive 210 * polls, stuff the clock filter. Next, 211 * determine the poll interval. If the 212 * peer is unfit for synchronization, 213 * increase it by one; otherwise, use 214 * the system poll interval. 215 */ 216 if (!(peer->reach & 0x07)) { 217 clock_filter(peer, 0., 0., 218 MAXDISPERSE); |
219 clock_select(); |
220 } |
221 if (peer_unfit(peer)) 222 hpoll++; 223 else 224 hpoll = sys_poll; 225 if (peer->flags & FLAG_BURST) 226 peer->burst = NTP_BURST; |
227 } |
228 } else { 229 230 /* |
231 * Source rate control. If we are restrained, 232 * each burst consists of only one packet. |
233 */ |
234 if (memcmp((char *)&peer->refid, "RSTR", 4) == 235 0) 236 peer->burst = 0; |
237 else |
238 peer->burst--; 239 if (peer->burst == 0) { 240 /* 241 * If a broadcast client at this point, 242 * the burst has concluded, so we switch 243 * to client mode and purge the keylist, 244 * since no further transmissions will 245 * be made. 246 */ 247 if (peer->cast_flags & MDF_BCLNT) { 248 peer->hmode = MODE_BCLIENT; 249#ifdef OPENSSL 250 key_expire(peer); 251#endif /* OPENSSL */ 252 } 253 poll_update(peer, hpoll); 254 clock_select(); |
255 |
256 /* 257 * If ntpdate mode and the clock has not 258 * been set and all peers have completed 259 * the burst, we declare a successful 260 * failure. 261 */ 262 if (mode_ntpdate) { 263 peer_ntpdate--; 264 if (peer_ntpdate > 0) { 265 poll_update( 266 peer, hpoll); 267 return; 268 } 269 msyslog(LOG_NOTICE, 270 "no reply; clock not set"); 271 exit (0); 272 } 273 poll_update(peer, hpoll); 274 return; |
275 } |
276 } 277 } 278 peer->outdate = current_time; |
279 280 /* |
281 * Do not transmit if in broadcast cclient mode or access has 282 * been denied. |
283 */ 284 if (peer->hmode == MODE_BCLIENT || peer->flash & TEST4) { |
285 poll_update(peer, hpoll); |
286 return; |
287 288 /* 289 * Do not transmit in broadcast mode unless we are synchronized. 290 */ 291 } else if (peer->hmode == MODE_BROADCAST && sys_peer == NULL) { 292 poll_update(peer, hpoll); 293 return; |
294 } 295 peer_xmit(peer); |
296 poll_update(peer, hpoll); |
297} 298 299/* 300 * receive - Receive Procedure. See section 3.4.3 in the specification. 301 */ 302void 303receive( 304 struct recvbuf *rbufp 305 ) 306{ |
307 register struct peer *peer; /* peer structure pointer */ 308 register struct pkt *pkt; /* receive packet pointer */ 309 int hismode; /* packet mode */ 310 int restrict_mask; /* restrict bits */ 311 int has_mac; /* length of MAC field */ 312 int authlen; /* offset of MAC field */ 313 int is_authentic; /* cryptosum ok */ 314 keyid_t skeyid = 0; /* key ID */ 315 struct sockaddr_storage *dstadr_sin; /* active runway */ 316 struct peer *peer2; /* aux peer structure pointer */ 317 l_fp p_org; /* originate timestamp */ 318 l_fp p_xmt; /* transmit timestamp */ 319#ifdef OPENSSL 320 keyid_t tkeyid = 0; /* temporary key ID */ 321 keyid_t pkeyid = 0; /* previous key ID */ 322 struct autokey *ap; /* autokey structure pointer */ 323 int rval; /* cookie snatcher */ 324#endif /* OPENSSL */ |
325 int retcode = AM_NOMATCH; 326 327 /* 328 * Monitor the packet and get restrictions. Note that the packet 329 * length for control and private mode packets must be checked 330 * by the service routines. Note that no statistics counters are 331 * recorded for restrict violations, since these counters are in 332 * the restriction routine. Note the careful distinctions here 333 * between a packet with a format error and a packet that is 334 * simply discarded without prejudice. Some restrictions have to 335 * be handled later in order to generate a kiss-of-death packet. 336 */ |
337 /* 338 * Bogus port check is before anything, since it probably 339 * reveals a clogging attack. 340 */ 341 sys_received++; 342 if (SRCPORT(&rbufp->recv_srcadr) == 0) { 343 sys_badlength++; 344 return; /* bogus port */ 345 } |
346 ntp_monitor(rbufp); 347 restrict_mask = restrictions(&rbufp->recv_srcadr); 348#ifdef DEBUG |
349 if (debug > 1) 350 printf("receive: at %ld %s<-%s restrict %03x\n", 351 current_time, stoa(&rbufp->dstadr->sin), 352 stoa(&rbufp->recv_srcadr), restrict_mask); |
353#endif |
354 if (restrict_mask & RES_IGNORE) { 355 sys_restricted++; |
356 return; /* no anything */ |
357 } |
358 pkt = &rbufp->recv_pkt; 359 hismode = (int)PKT_MODE(pkt->li_vn_mode); 360 if (hismode == MODE_PRIVATE) { 361 if (restrict_mask & RES_NOQUERY) { 362 sys_restricted++; |
363 return; /* no query private */ |
364 } |
365 process_private(rbufp, ((restrict_mask & 366 RES_NOMODIFY) == 0)); 367 return; 368 } |
369 if (hismode == MODE_CONTROL) { 370 if (restrict_mask & RES_NOQUERY) { 371 sys_restricted++; |
372 return; /* no query control */ |
373 } |
374 process_control(rbufp, restrict_mask); 375 return; 376 } |
377 if (restrict_mask & RES_DONTSERVE) { 378 sys_restricted++; 379 return; /* no time */ 380 } |
381 if (rbufp->recv_length < LEN_PKT_NOMAC) { 382 sys_badlength++; 383 return; /* runt packet */ 384 } |
385 386 /* 387 * Version check must be after the query packets, since they 388 * intentionally use early version. 389 */ 390 if (PKT_VERSION(pkt->li_vn_mode) == NTP_VERSION) { 391 sys_newversionpkt++; /* new version */ 392 } else if (!(restrict_mask & RES_VERSION) && 393 PKT_VERSION(pkt->li_vn_mode) >= NTP_OLDVERSION) { 394 sys_oldversionpkt++; /* previous version */ 395 } else { 396 sys_unknownversion++; 397 return; /* old version */ 398 } |
399 400 /* |
401 * Figure out his mode and validate the packet. This has some 402 * legacy raunch that probably should be removed. In very early 403 * NTP versions mode 0 was equivalent to what later versions 404 * would interpret as client mode. |
405 */ |
406 if (hismode == MODE_UNSPEC) { |
407 if (PKT_VERSION(pkt->li_vn_mode) == NTP_OLDVERSION) { 408 hismode = MODE_CLIENT; 409 } else { 410 sys_badlength++; 411 return; /* invalid mode */ 412 } |
413 } 414 415 /* |
416 * Discard broadcast if not enabled as broadcast client. If 417 * Autokey, the wildcard interface cannot be used, so dump 418 * packets gettiing off the bus at that stop as well. This means 419 * that some systems with broken interface code, specifically 420 * Linux, will not work with Autokey. |
421 */ |
422 if (hismode == MODE_BROADCAST) { 423 if (!sys_bclient || restrict_mask & RES_NOPEER) { 424 sys_restricted++; 425 return; /* no client */ 426 } 427#ifdef OPENSSL 428 if (crypto_flags && rbufp->dstadr == any_interface) { 429 sys_restricted++; 430 return; /* no client */ 431 } 432#endif /* OPENSSL */ 433 } |
434 435 /* 436 * Parse the extension field if present. We figure out whether 437 * an extension field is present by measuring the MAC size. If 438 * the number of words following the packet header is 0 or 1, no 439 * MAC is present and the packet is not authenticated. If 1, the 440 * packet is a reply to a previous request that failed to 441 * authenticate. If 3, the packet is authenticated with DES; if 442 * 5, the packet is authenticated with MD5. If greater than 5, 443 * an extension field is present. If 2 or 4, the packet is a 444 * runt and goes poof! with a brilliant flash. 445 */ |
446 authlen = LEN_PKT_NOMAC; |
447 has_mac = rbufp->recv_length - authlen; 448 while (has_mac > 0) { |
449 int temp; 450 451 if (has_mac % 4 != 0 || has_mac < 0) { 452 sys_badlength++; |
453 return; /* bad MAC length */ |
454 } 455 if (has_mac == 1 * 4 || has_mac == 3 * 4 || has_mac == 456 MAX_MAC_LEN) { 457 skeyid = ntohl(((u_int32 *)pkt)[authlen / 4]); 458 break; 459 460 } else if (has_mac > MAX_MAC_LEN) { 461 temp = ntohl(((u_int32 *)pkt)[authlen / 4]) & 462 0xffff; |
463 if (temp < 4 || temp > NTP_MAXEXTEN || temp % 4 464 != 0) { |
465 sys_badlength++; |
466 return; /* bad MAC length */ |
467 } 468 authlen += temp; |
469 has_mac -= temp; |
470 } else { 471 sys_badlength++; |
472 return; /* bad MAC length */ |
473 } 474 } |
475#ifdef OPENSSL 476 pkeyid = tkeyid = 0; 477#endif /* OPENSSL */ |
478 479 /* 480 * We have tossed out as many buggy packets as possible early in 481 * the game to reduce the exposure to a clogging attack. Now we 482 * have to burn some cycles to find the association and 483 * authenticate the packet if required. Note that we burn only |
484 * MD5 cycles, again to reduce exposure. There may be no |
485 * matching association and that's okay. 486 * 487 * More on the autokey mambo. Normally the local interface is 488 * found when the association was mobilized with respect to a 489 * designated remote address. We assume packets arriving from 490 * the remote address arrive via this interface and the local 491 * address used to construct the autokey is the unicast address 492 * of the interface. However, if the sender is a broadcaster, --- 5 unchanged lines hidden (view full) --- 498 peer = findpeer(&rbufp->recv_srcadr, rbufp->dstadr, rbufp->fd, 499 hismode, &retcode); 500 is_authentic = 0; 501 dstadr_sin = &rbufp->dstadr->sin; 502 if (has_mac == 0) { 503#ifdef DEBUG 504 if (debug) 505 printf("receive: at %ld %s<-%s mode %d code %d\n", |
506 current_time, stoa(&rbufp->dstadr->sin), 507 stoa(&rbufp->recv_srcadr), hismode, 508 retcode); |
509#endif 510 } else { |
511#ifdef OPENSSL |
512 /* 513 * For autokey modes, generate the session key 514 * and install in the key cache. Use the socket 515 * broadcast or unicast address as appropriate. 516 */ 517 if (skeyid > NTP_MAXKEY) { 518 519 /* --- 26 unchanged lines hidden (view full) --- 546 /* 547 * For broadcaster, use the interface 548 * broadcast address when available; 549 * otherwise, use the unicast address 550 * found when the association was 551 * mobilized. 552 */ 553 pkeyid = 0; |
554 if (!SOCKNUL(&rbufp->dstadr->bcast)) |
555 dstadr_sin = 556 &rbufp->dstadr->bcast; 557 } else if (peer == NULL) { 558 pkeyid = session_key( 559 &rbufp->recv_srcadr, dstadr_sin, 0, 560 sys_private, 0); 561 } else { |
562 pkeyid = peer->pcookie; |
563 } 564 565 /* 566 * The session key includes both the public 567 * values and cookie. In case of an extension 568 * field, the cookie used for authentication 569 * purposes is zero. Note the hash is saved for 570 * use later in the autokey mambo. --- 6 unchanged lines hidden (view full) --- 577 skeyid, pkeyid, 0); 578 } else { 579 tkeyid = session_key( 580 &rbufp->recv_srcadr, dstadr_sin, 581 skeyid, pkeyid, 2); 582 } 583 584 } |
585#endif /* OPENSSL */ |
586 587 /* 588 * Compute the cryptosum. Note a clogging attack may 589 * succeed in bloating the key cache. If an autokey, 590 * purge it immediately, since we won't be needing it |
591 * again. If the packet is authentic, it may mobilize an 592 * association. |
593 */ 594 if (authdecrypt(skeyid, (u_int32 *)pkt, authlen, |
595 has_mac)) { |
596 is_authentic = 1; |
597 restrict_mask &= ~RES_DONTTRUST; 598 } else { |
599 sys_badauth++; |
600 } 601#ifdef OPENSSL |
602 if (skeyid > NTP_MAXKEY) 603 authtrust(skeyid, 0); |
604#endif /* OPENSSL */ |
605#ifdef DEBUG 606 if (debug) 607 printf( 608 "receive: at %ld %s<-%s mode %d code %d keyid %08x len %d mac %d auth %d\n", |
609 current_time, stoa(dstadr_sin), 610 stoa(&rbufp->recv_srcadr), hismode, retcode, |
611 skeyid, authlen, has_mac, 612 is_authentic); 613#endif 614 } 615 616 /* 617 * The association matching rules are implemented by a set of 618 * routines and a table in ntp_peer.c. A packet matching an 619 * association is processed by that association. If not and 620 * certain conditions prevail, then an ephemeral association is 621 * mobilized: a broadcast packet mobilizes a broadcast client |
622 * aassociation; a manycast server packet mobilizes a manycast 623 * client association; a symmetric active packet mobilizes a 624 * symmetric passive association. And, the adventure 625 * continues... |
626 */ 627 switch (retcode) { 628 case AM_FXMIT: 629 630 /* 631 * This is a client mode packet not matching a known 632 * association. If from a manycast client we run a few 633 * sanity checks before deciding to send a unicast 634 * server response. Otherwise, it must be a client 635 * request, so send a server response and go home. 636 */ 637 if (sys_manycastserver && (rbufp->dstadr->flags & 638 INT_MULTICAST)) { 639 640 /* |
641 * There is no reason to respond to a request if 642 * our time is worse than the manycaster or it 643 * has already synchronized to us. |
644 */ |
645 if (sys_peer == NULL || 646 PKT_TO_STRATUM(pkt->stratum) < 647 sys_stratum || (sys_cohort && 648 PKT_TO_STRATUM(pkt->stratum) == 649 sys_stratum) || 650 rbufp->dstadr->addr_refid == pkt->refid) 651 return; /* manycast dropped */ |
652 } 653 654 /* 655 * Note that we don't require an authentication check 656 * here, since we can't set the system clock; but, we do |
657 * send a crypto-NAK to tell the caller about this. |
658 */ |
659 if (has_mac && !is_authentic) 660 fast_xmit(rbufp, MODE_SERVER, 0, restrict_mask); 661 else |
662 fast_xmit(rbufp, MODE_SERVER, skeyid, 663 restrict_mask); |
664 return; 665 666 case AM_MANYCAST: 667 668 /* 669 * This is a server mode packet returned in response to 670 * a client mode packet sent to a multicast group 671 * address. The originate timestamp is a good nonce to 672 * reliably associate the reply with what was sent. If 673 * there is no match, that's curious and could be an 674 * intruder attempting to clog, so we just ignore it. 675 * |
676 * First, make sure the packet is authentic and not 677 * restricted. If so and the manycast association is 678 * found, we mobilize a client association and copy 679 * pertinent variables from the manycast association to 680 * the new client association. |
681 * 682 * There is an implosion hazard at the manycast client, 683 * since the manycast servers send the server packet |
684 * immediately. If the guy is already here, don't fire 685 * up a duplicate. |
686 */ |
687 if (restrict_mask & RES_DONTTRUST) { 688 sys_restricted++; 689 return; /* no trust */ 690 } |
691 |
692 if (sys_authenticate && !is_authentic) 693 return; /* bad auth */ |
694 |
695 if ((peer2 = findmanycastpeer(rbufp)) == NULL) 696 return; /* no assoc match */ 697 698 if ((peer = newpeer(&rbufp->recv_srcadr, rbufp->dstadr, |
699 MODE_CLIENT, PKT_VERSION(pkt->li_vn_mode), |
700 NTP_MINDPOLL, NTP_MAXDPOLL, FLAG_IBURST, MDF_UCAST | 701 MDF_ACLNT, 0, skeyid)) == NULL) 702 return; /* system error */ 703 704 /* 705 * We don't need these, but it warms the billboards. 706 */ 707 peer->ttl = peer2->ttl; |
708 break; 709 710 case AM_NEWPASS: 711 712 /* 713 * This is the first packet received from a symmetric |
714 * active peer. First, make sure it is authentic and not 715 * restricted. If so, mobilize a passive association. 716 * If authentication fails send a crypto-NAK; otherwise, 717 * kiss the frog. |
718 */ |
719 if (restrict_mask & RES_DONTTRUST) { 720 sys_restricted++; 721 return; /* no trust */ 722 } 723 if (sys_authenticate && !is_authentic) { |
724 fast_xmit(rbufp, MODE_PASSIVE, 0, 725 restrict_mask); |
726 return; /* bad auth */ |
727 } |
728 if ((peer = newpeer(&rbufp->recv_srcadr, rbufp->dstadr, |
729 MODE_PASSIVE, PKT_VERSION(pkt->li_vn_mode), |
730 NTP_MINDPOLL, NTP_MAXDPOLL, 0, MDF_UCAST, 0, 731 skeyid)) == NULL) 732 return; /* system error */ 733 |
734 break; 735 736 case AM_NEWBCL: 737 738 /* 739 * This is the first packet received from a broadcast |
740 * server. First, make sure it is authentic and not 741 * restricted and that we are a broadcast client. If so, 742 * mobilize a broadcast client association. We don't 743 * kiss any frogs here. |
744 */ |
745 if (restrict_mask & RES_DONTTRUST) { 746 sys_restricted++; 747 return; /* no trust */ 748 } 749 if (sys_authenticate && !is_authentic) 750 return; /* bad auth */ |
751 |
752 if (!sys_bclient) 753 return; /* not a client */ 754 755 if ((peer = newpeer(&rbufp->recv_srcadr, rbufp->dstadr, |
756 MODE_CLIENT, PKT_VERSION(pkt->li_vn_mode), |
757 NTP_MINDPOLL, NTP_MAXDPOLL, FLAG_MCAST | 758 FLAG_IBURST, MDF_BCLNT, 0, skeyid)) == NULL) 759 return; /* system error */ 760#ifdef OPENSSL 761 /* 762 * Danger looms. If this is autokey, go process the 763 * extension fields. If something goes wrong, abandon 764 * ship and don't trust subsequent packets. 765 */ 766 if (crypto_flags) { 767 if ((rval = crypto_recv(peer, rbufp)) != 768 XEVNT_OK) { 769 struct sockaddr_storage mskadr_sin; 770 771 unpeer(peer); 772 sys_restricted++; 773 SET_HOSTMASK(&mskadr_sin, 774 rbufp->recv_srcadr.ss_family); 775 hack_restrict(RESTRICT_FLAGS, 776 &rbufp->recv_srcadr, &mskadr_sin, 777 0, RES_DONTTRUST | RES_TIMEOUT); 778#ifdef DEBUG 779 if (debug) 780 printf( 781 "packet: bad exten %x\n", 782 rval); 783#endif 784 } 785 } 786#endif /* OPENSSL */ |
787 return; 788 789 case AM_POSSBCL: |
790 791 /* 792 * This is a broadcast packet received in client mode. 793 * It could happen if the initial client/server volley 794 * is not complete before the next broadcast packet is 795 * received. Be liberal in what we accept. 796 */ |
797 case AM_PROCPKT: 798 799 /* |
800 * This is a symmetric mode packet received in symmetric 801 * mode, a server packet received in client mode or a 802 * broadcast packet received in broadcast client mode. 803 * If it is restricted, this is very strange because it 804 * is rude to send a packet to a restricted address. If 805 * anyway, flash a restrain kiss and skedaddle to 806 * Seattle. If not authentic, leave a light on and 807 * continue. |
808 */ |
809 peer->flash = 0; 810 if (restrict_mask & RES_DONTTRUST) { 811 sys_restricted++; 812 if (peer->flags & FLAG_CONFIG) 813 peer_clear(peer, "RSTR"); 814 else 815 unpeer(peer); 816 return; /* no trust */ 817 } 818 if (has_mac && !is_authentic) 819 peer->flash |= TEST5; /* bad auth */ |
820 break; 821 822 default: 823 824 /* |
825 * Invalid mode combination. This happens when a passive 826 * mode packet arrives and matches another passive 827 * association or no association at all, or when a 828 * server mode packet arrives and matches a broadcast 829 * client association. This is usually the result of 830 * reconfiguring a client on-fly. If authenticated 831 * passive mode packet, send a crypto-NAK; otherwise, 832 * ignore it. |
833 */ |
834 if (has_mac && hismode == MODE_PASSIVE) 835 fast_xmit(rbufp, MODE_ACTIVE, 0, restrict_mask); |
836#ifdef DEBUG 837 if (debug) 838 printf("receive: bad protocol %d\n", retcode); 839#endif 840 return; 841 } 842 843 /* |
844 * We do a little homework. Note we can get here with an 845 * authentication error. We Need to do this in order to validate 846 * a crypto-NAK later. Note the order of processing; it is very 847 * important to avoid livelocks, deadlocks and lockpicks. |
848 */ |
849 peer->timereceived = current_time; 850 peer->received++; |
851 if (peer->flash & TEST5) 852 peer->flags &= ~FLAG_AUTHENTIC; 853 else 854 peer->flags |= FLAG_AUTHENTIC; 855 NTOHL_FP(&pkt->org, &p_org); 856 NTOHL_FP(&pkt->xmt, &p_xmt); |
857 858 /* |
859 * If the packet is an old duplicate, we let it through so the 860 * extension fields will be processed. |
861 */ |
862 if (L_ISEQU(&peer->org, &p_xmt)) { /* test 1 */ 863 peer->flash |= TEST1; /* dupe */ 864 /* fall through */ 865 866 /* 867 * For broadcast server mode, loopback checking is disabled. An 868 * authentication error probably means the server restarted or 869 * rolled a new private value. If so, dump the association 870 * and wait for the next message. 871 */ 872 } else if (hismode == MODE_BROADCAST) { 873 if (peer->flash & TEST5) { 874 unpeer(peer); 875 return; 876 } 877 /* fall through */ 878 879 /* 880 * For server and symmetric modes, if the association transmit 881 * timestamp matches the packet originate timestamp, loopback is 882 * confirmed. Note in symmetric modes this also happens when the 883 * first packet from the active peer arrives at the newly 884 * mobilized passive peer. An authentication error probably 885 * means the server or peer restarted or rolled a new private 886 * value, but could be an intruder trying to stir up trouble. 887 * However, if this is a crypto-NAK, we know it is authentic, so 888 * dump the association and wait for the next message. 889 */ 890 } else if (L_ISEQU(&peer->xmt, &p_org)) { 891 if (peer->flash & TEST5) { 892 if (has_mac == 4 && pkt->exten[0] == 0) { 893 if (peer->flags & FLAG_CONFIG) 894 peer_clear(peer, "AUTH"); 895 else 896 unpeer(peer); 897 } 898 return; 899 } 900 /* fall through */ 901 902 /* 903 * If the client or passive peer has never transmitted anything, 904 * this is either the first message from a symmetric peer or 905 * possibly a duplicate received before the transmit timeout. 906 * Pass it on. 907 */ 908 } else if (L_ISZERO(&peer->xmt)) { 909 /* fall through */ 910 911 /* 912 * Now it gets interesting. We have transmitted at least one 913 * packet. If the packet originate timestamp is nonzero, it 914 * does not match the association transmit timestamp, which is a 915 * loopback error. This error might mean a manycast server has 916 * answered a manycast honk from us and we already have an 917 * association for him, in which case quietly drop the packet 918 * here. It might mean an old duplicate, dropped packet or 919 * intruder replay, in which case we drop it later after 920 * extension field processing, but never let it touch the time 921 * values. 922 */ 923 } else if (!L_ISZERO(&p_org)) { 924 if (peer->cast_flags & MDF_ACLNT) 925 return; /* not a client */ 926 927 peer->flash |= TEST2; 928 /* fall through */ 929 930 /* 931 * The packet originate timestamp is zero, meaning the other guy 932 * either didn't receive the first packet or died and restarted. 933 * If the association originate timestamp is zero, this is the 934 * first packet received, so we pass it on. 935 */ 936 } else if (L_ISZERO(&peer->org)) { 937 /* fall through */ 938 939 /* 940 * The other guy has restarted and we are still on the wire. We 941 * should demobilize/clear and get out of Dodge. If this is 942 * symmetric mode, we should also send a crypto-NAK. 943 */ |
944 } else { |
945 if (hismode == MODE_ACTIVE) 946 fast_xmit(rbufp, MODE_PASSIVE, 0, 947 restrict_mask); 948 else if (hismode == MODE_PASSIVE) 949 fast_xmit(rbufp, MODE_ACTIVE, 0, restrict_mask); 950#if DEBUG |
951 if (debug) |
952 printf("receive: dropped %03x\n", peer->flash); |
953#endif |
954 if (peer->flags & FLAG_CONFIG) 955 peer_clear(peer, "DROP"); 956 else 957 unpeer(peer); |
958 return; 959 } |
960 if (peer->flash & ~TEST2) { 961 return; 962 } |
963 |
964#ifdef OPENSSL |
965 /* 966 * More autokey dance. The rules of the cha-cha are as follows: 967 * 968 * 1. If there is no key or the key is not auto, do nothing. 969 * |
970 * 2. If this packet is in response to the one just previously 971 * sent or from a broadcast server, do the extension fields. 972 * Otherwise, assume bogosity and bail out. 973 * 974 * 3. If an extension field contains a verified signature, it is |
975 * self-authenticated and we sit the dance. 976 * |
977 * 4. If this is a server reply, check only to see that the |
978 * transmitted key ID matches the received key ID. 979 * |
980 * 5. Check to see that one or more hashes of the current key ID |
981 * matches the previous key ID or ultimate original key ID 982 * obtained from the broadcaster or symmetric peer. If no 983 * match, sit the dance and wait for timeout. 984 */ |
985 if (crypto_flags && (peer->flags & FLAG_SKEY)) { |
986 peer->flash |= TEST10; |
987 rval = crypto_recv(peer, rbufp); 988 if (rval != XEVNT_OK) { 989 /* fall through */ 990 991 } else if (hismode == MODE_SERVER) { |
992 if (skeyid == peer->keyid) 993 peer->flash &= ~TEST10; 994 } else if (!peer->flash & TEST10) { 995 peer->pkeyid = skeyid; |
996 } else if ((ap = (struct autokey *)peer->recval.ptr) != 997 NULL) { |
998 int i; 999 1000 for (i = 0; ; i++) { 1001 if (tkeyid == peer->pkeyid || |
1002 tkeyid == ap->key) { |
1003 peer->flash &= ~TEST10; 1004 peer->pkeyid = skeyid; 1005 break; 1006 } |
1007 if (i > ap->seq) |
1008 break; 1009 tkeyid = session_key( 1010 &rbufp->recv_srcadr, dstadr_sin, 1011 tkeyid, pkeyid, 0); 1012 } 1013 } |
1014 if (!(peer->crypto & CRYPTO_FLAG_PROV)) /* test 11 */ 1015 peer->flash |= TEST11; /* not proventic */ |
1016 1017 /* |
1018 * If the transmit queue is nonempty, clamp the host 1019 * poll interval to the packet poll interval. |
1020 */ |
1021 if (peer->cmmd != 0) { 1022 peer->ppoll = pkt->ppoll; 1023 poll_update(peer, 0); 1024 } 1025 1026 /* 1027 * If the return code from extension field processing is 1028 * not okay, we scrub the association and start over. 1029 */ 1030 if (rval != XEVNT_OK) { 1031 1032 /* 1033 * If the return code is bad, the crypto machine 1034 * may be jammed or an intruder may lurk. First, 1035 * we demobilize the association, then see if 1036 * the error is recoverable. 1037 */ 1038 if (peer->flags & FLAG_CONFIG) 1039 peer_clear(peer, "CRYP"); 1040 else 1041 unpeer(peer); |
1042#ifdef DEBUG 1043 if (debug) |
1044 printf("packet: bad exten %x\n", rval); 1045#endif 1046 return; 1047 } 1048 1049 /* 1050 * If TEST10 is lit, the autokey sequence has broken, 1051 * which probably means the server has refreshed its 1052 * private value. We reset the poll interval to the 1053 & minimum and scrub the association clean. 1054 */ 1055 if (peer->flash & TEST10 && peer->crypto & 1056 CRYPTO_FLAG_AUTO) { 1057 poll_update(peer, peer->minpoll); 1058#ifdef DEBUG 1059 if (debug) 1060 printf( 1061 "packet: bad auto %03x\n", |
1062 peer->flash); 1063#endif |
1064 if (peer->flags & FLAG_CONFIG) 1065 peer_clear(peer, "AUTO"); 1066 else 1067 unpeer(peer); |
1068 return; 1069 } |
1070 } |
1071#endif /* OPENSSL */ |
1072 1073 /* 1074 * We have survived the gaunt. Forward to the packet routine. If 1075 * a symmetric passive association has been mobilized and the 1076 * association doesn't deserve to live, it will die in the |
1077 * transmit routine if not reachable after timeout. However, if 1078 * either symmetric mode and the crypto code has something 1079 * urgent to say, we expedite the response. |
1080 */ 1081 process_packet(peer, pkt, &rbufp->recv_time); 1082} 1083 1084 1085/* 1086 * process_packet - Packet Procedure, a la Section 3.4.4 of the 1087 * specification. Or almost, at least. If we're in here we have a 1088 * reasonable expectation that we will be having a long term 1089 * relationship with this host. 1090 */ 1091void 1092process_packet( 1093 register struct peer *peer, 1094 register struct pkt *pkt, |
1095 l_fp *recv_ts |
1096 ) 1097{ |
1098 l_fp t34, t21; 1099 double p_offset, p_del, p_disp; 1100 double dtemp; 1101 l_fp p_rec, p_xmt, p_org, p_reftime; 1102 l_fp ci; 1103 u_char pmode, pleap, pstratum; |
1104 1105 /* 1106 * Swap header fields and keep the books. The books amount to 1107 * the receive timestamp and poll interval in the header. We 1108 * need these even if there are other problems in order to crank 1109 * up the state machine. 1110 */ 1111 sys_processed++; 1112 peer->processed++; 1113 p_del = FPTOD(NTOHS_FP(pkt->rootdelay)); 1114 p_disp = FPTOD(NTOHS_FP(pkt->rootdispersion)); 1115 NTOHL_FP(&pkt->reftime, &p_reftime); 1116 NTOHL_FP(&pkt->rec, &p_rec); 1117 NTOHL_FP(&pkt->xmt, &p_xmt); |
1118 pmode = PKT_MODE(pkt->li_vn_mode); 1119 pleap = PKT_LEAP(pkt->li_vn_mode); 1120 if (pmode != MODE_BROADCAST) |
1121 NTOHL_FP(&pkt->org, &p_org); 1122 else 1123 p_org = peer->rec; |
1124 pstratum = PKT_TO_STRATUM(pkt->stratum); |
1125 1126 /* |
1127 * Test for unsynchronized server. |
1128 */ |
1129 if (L_ISHIS(&peer->org, &p_xmt)) /* count old packets */ 1130 peer->oldpkt++; |
1131 if (pmode != MODE_BROADCAST && (L_ISZERO(&p_rec) || 1132 L_ISZERO(&p_org))) /* test 3 */ |
1133 peer->flash |= TEST3; /* unsynch */ |
1134 if (L_ISZERO(&p_xmt)) /* test 3 */ 1135 peer->flash |= TEST3; /* unsynch */ |
1136 1137 /* |
1138 * If any tests fail, the packet is discarded leaving only the 1139 * timestamps, which are enough to get the protocol started. The 1140 * originate timestamp is copied from the packet transmit 1141 * timestamp and the receive timestamp is copied from the 1142 * packet receive timestamp. If okay so far, we save the leap, 1143 * stratum and refid for billboards. |
1144 */ |
1145 peer->org = p_xmt; 1146 peer->rec = *recv_ts; |
1147 if (peer->flash) { 1148#ifdef DEBUG 1149 if (debug) |
1150 printf("packet: bad data %03x from address: %s\n", 1151 peer->flash, stoa(&peer->srcadr)); |
1152#endif 1153 return; 1154 } |
1155 peer->leap = pleap; 1156 peer->stratum = pstratum; 1157 peer->refid = pkt->refid; |
1158 1159 /* |
1160 * Test for valid peer data (tests 6-8) 1161 */ 1162 ci = p_xmt; 1163 L_SUB(&ci, &p_reftime); 1164 LFPTOD(&ci, dtemp); |
1165 if (pleap == LEAP_NOTINSYNC || /* test 6 */ |
1166 pstratum >= STRATUM_UNSPEC || dtemp < 0) 1167 peer->flash |= TEST6; /* bad synch */ |
1168 if (!(peer->flags & FLAG_CONFIG) && sys_peer != NULL) { /* test 7 */ 1169 if (pstratum > sys_stratum && pmode != MODE_ACTIVE) |
1170 peer->flash |= TEST7; /* bad stratum */ |
1171 } |
1172 if (p_del < 0 || p_disp < 0 || p_del / /* test 8 */ |
1173 2 + p_disp >= MAXDISPERSE) |
1174 peer->flash |= TEST8; /* bad peer values */ 1175 1176 /* 1177 * If any tests fail at this point, the packet is discarded. 1178 */ |
1179 if (peer->flash) { 1180#ifdef DEBUG 1181 if (debug) 1182 printf("packet: bad header %03x\n", 1183 peer->flash); 1184#endif 1185 return; 1186 } 1187 1188 /* 1189 * The header is valid. Capture the remaining header values and 1190 * mark as reachable. 1191 */ 1192 record_raw_stats(&peer->srcadr, &peer->dstadr->sin, &p_org, 1193 &p_rec, &p_xmt, &peer->rec); |
1194 peer->pmode = pmode; |
1195 peer->ppoll = pkt->ppoll; 1196 peer->precision = pkt->precision; 1197 peer->rootdelay = p_del; 1198 peer->rootdispersion = p_disp; |
1199 peer->reftime = p_reftime; 1200 if (!(peer->reach)) { 1201 report_event(EVNT_REACH, peer); 1202 peer->timereachable = current_time; 1203 } 1204 peer->reach |= 1; 1205 peer->unreach = 0; |
1206 poll_update(peer, 0); |
1207 1208 /* 1209 * If running in a client/server association, calculate the 1210 * clock offset c, roundtrip delay d and dispersion e. We use 1211 * the equations (reordered from those in the spec). Note that, 1212 * in a broadcast association, org has been set to the time of 1213 * last reception. Note the computation of dispersion includes 1214 * the system precision plus that due to the frequency error 1215 * since the originate time. 1216 * |
1217 * Let t1 = p_org, t2 = p_rec, t3 = p_xmt, t4 = peer->rec: |
1218 */ |
1219 t34 = p_xmt; /* t3 - t4 */ 1220 L_SUB(&t34, &peer->rec); 1221 t21 = p_rec; /* t2 - t1 */ 1222 L_SUB(&t21, &p_org); 1223 ci = peer->rec; /* t4 - t1 */ 1224 L_SUB(&ci, &p_org); 1225 LFPTOD(&ci, p_disp); 1226 p_disp = clock_phi * max(p_disp, LOGTOD(sys_precision)); |
1227 1228 /* 1229 * If running in a broadcast association, the clock offset is 1230 * (t1 - t0) corrected by the one-way delay, but we can't 1231 * measure that directly. Therefore, we start up in MODE_CLIENT 1232 * mode, set FLAG_MCAST and exchange eight messages to determine 1233 * the clock offset. When the last message is sent, we switch to 1234 * MODE_BCLIENT mode. The next broadcast message after that 1235 * computes the broadcast offset and clears FLAG_MCAST. 1236 */ |
1237 ci = t34; |
1238 if (pmode == MODE_BROADCAST) { 1239 if (peer->flags & FLAG_MCAST) { 1240 LFPTOD(&ci, p_offset); 1241 peer->estbdelay = peer->offset - p_offset; 1242 if (peer->hmode == MODE_CLIENT) 1243 return; 1244 1245 peer->flags &= ~FLAG_MCAST; 1246 } |
1247 DTOLFP(peer->estbdelay, &t34); 1248 L_ADD(&ci, &t34); |
1249 p_del = peer->delay; 1250 } else { |
1251 L_ADD(&ci, &t21); /* (t2 - t1) + (t3 - t4) */ |
1252 L_RSHIFT(&ci); |
1253 L_SUB(&t21, &t34); /* (t2 - t1) - (t3 - t4) */ 1254 LFPTOD(&t21, p_del); |
1255 } 1256 p_del = max(p_del, LOGTOD(sys_precision)); 1257 LFPTOD(&ci, p_offset); 1258 if ((peer->rootdelay + p_del) / 2. + peer->rootdispersion + |
1259 p_disp >= MAXDISPERSE) /* test 9 */ 1260 peer->flash |= TEST9; /* bad root distance */ |
1261 1262 /* 1263 * If any flasher bits remain set at this point, abandon ship. 1264 * Otherwise, forward to the clock filter. 1265 */ 1266 if (peer->flash) { 1267#ifdef DEBUG 1268 if (debug) --- 16 unchanged lines hidden (view full) --- 1285static void 1286clock_update(void) 1287{ 1288 u_char oleap; 1289 u_char ostratum; 1290 1291 /* 1292 * Reset/adjust the system clock. Do this only if there is a |
1293 * system peer and the peer epoch is not older than the last 1294 * update. |
1295 */ 1296 if (sys_peer == NULL) 1297 return; |
1298 if (sys_peer->epoch <= last_time) |
1299 return; |
1300#ifdef DEBUG 1301 if (debug) 1302 printf("clock_update: at %ld assoc %d \n", current_time, 1303 peer_associations); 1304#endif 1305 oleap = sys_leap; 1306 ostratum = sys_stratum; 1307 switch (local_clock(sys_peer, sys_offset, sys_syserr)) { 1308 1309 /* 1310 * Clock is too screwed up. Just exit for now. 1311 */ 1312 case -1: |
1313 report_event(EVNT_SYSFAULT, NULL); 1314 exit (-1); |
1315 /*NOTREACHED*/ 1316 1317 /* 1318 * Clock was stepped. Flush all time values of all peers. 1319 */ 1320 case 1: 1321 clear_all(); 1322 sys_peer = NULL; 1323 sys_stratum = STRATUM_UNSPEC; |
1324 memcpy(&sys_refid, "STEP", 4); |
1325 sys_poll = NTP_MINPOLL; |
1326 report_event(EVNT_CLOCKRESET, NULL); 1327#ifdef OPENSSL 1328 if (oleap != LEAP_NOTINSYNC) 1329 expire_all(); 1330#endif /* OPENSSL */ |
1331 break; 1332 1333 /* 1334 * Update the system stratum, leap bits, root delay, root 1335 * dispersion, reference ID and reference time. We also update 1336 * select dispersion and max frequency error. If the leap 1337 * changes, we gotta reroll the keys. 1338 */ 1339 default: |
1340 sys_stratum = (u_char) (sys_peer->stratum + 1); 1341 if (sys_stratum == 1 || sys_stratum == STRATUM_UNSPEC) |
1342 sys_refid = sys_peer->refid; 1343 else |
1344 sys_refid = sys_peer_refid; |
1345 sys_reftime = sys_peer->rec; 1346 sys_rootdelay = sys_peer->rootdelay + sys_peer->delay; 1347 sys_leap = leap_consensus; |
1348 if (oleap == LEAP_NOTINSYNC) { 1349 report_event(EVNT_SYNCCHG, NULL); 1350#ifdef OPENSSL 1351 expire_all(); 1352#endif /* OPENSSL */ 1353 } |
1354 } |
1355 if (ostratum != sys_stratum) |
1356 report_event(EVNT_PEERSTCHG, NULL); |
1357} 1358 1359 1360/* 1361 * poll_update - update peer poll interval 1362 */ 1363void 1364poll_update( 1365 struct peer *peer, |
1366 int hpoll |
1367 ) 1368{ |
1369#ifdef OPENSSL 1370 int oldpoll; 1371#endif /* OPENSSL */ |
1372 1373 /* 1374 * A little foxtrot to determine what controls the poll 1375 * interval. If the peer is reachable, but the last four polls 1376 * have not been answered, use the minimum. If declared 1377 * truechimer, use the system poll interval. This allows each 1378 * association to ramp up the poll interval for useless sources 1379 * and to clamp it to the minimum when first starting up. 1380 */ |
1381#ifdef OPENSSL |
1382 oldpoll = peer->kpoll; |
1383#endif /* OPENSSL */ 1384 if (hpoll > 0) { 1385 if (hpoll > peer->maxpoll) 1386 peer->hpoll = peer->maxpoll; 1387 else if (hpoll < peer->minpoll) 1388 peer->hpoll = peer->minpoll; 1389 else 1390 peer->hpoll = (u_char)hpoll; 1391 } |
1392 1393 /* |
1394 * Bit of adventure here. If during a burst and not a poll, just 1395 * slink away. If a poll, figure what the next poll should be. 1396 * If a burst is pending and a reference clock or a pending 1397 * crypto response, delay for one second. If the first sent in a 1398 * burst, delay ten seconds for the modem to come up. For others 1399 * in the burst, delay two seconds. |
1400 * 1401 * In case of manycast server, make the poll interval, which is 1402 * axtually the manycast beacon interval, eight times the system 1403 * poll interval. Normally when the host poll interval settles |
1404 * up to 1024 s, the beacon interval settles up to 2.3 hours. |
1405 */ |
1406#ifdef OPENSSL 1407 if (peer->cmmd != NULL && (sys_leap != LEAP_NOTINSYNC || 1408 peer->crypto)) { 1409 peer->nextdate = current_time + RESP_DELAY; 1410 } else if (peer->burst > 0) { 1411#else /* OPENSSL */ |
1412 if (peer->burst > 0) { |
1413#endif /* OPENSSL */ 1414 if (hpoll == 0 && peer->nextdate != current_time) |
1415 return; 1416#ifdef REFCLOCK 1417 else if (peer->flags & FLAG_REFCLOCK) |
1418 peer->nextdate += RESP_DELAY; |
1419#endif |
1420 else if (peer->flags & (FLAG_IBURST | FLAG_BURST) && 1421 peer->burst == NTP_BURST) 1422 peer->nextdate += sys_calldelay; |
1423 else |
1424 peer->nextdate += BURST_DELAY; |
1425 } else if (peer->cast_flags & MDF_ACAST) { |
1426 if (sys_survivors >= sys_minclock || peer->ttl >= 1427 sys_ttlmax) 1428 peer->kpoll = (u_char) (peer->hpoll + 3); |
1429 else |
1430 peer->kpoll = peer->hpoll; |
1431 peer->nextdate = peer->outdate + RANDPOLL(peer->kpoll); 1432 } else { |
1433 peer->kpoll = (u_char) max(min(peer->ppoll, 1434 peer->hpoll), peer->minpoll); |
1435 peer->nextdate = peer->outdate + RANDPOLL(peer->kpoll); 1436 } 1437 if (peer->nextdate < current_time) 1438 peer->nextdate = current_time; |
1439#ifdef OPENSSL |
1440 /* 1441 * Bit of crass arrogance at this point. If the poll interval 1442 * has changed and we have a keylist, the lifetimes in the 1443 * keylist are probably bogus. In this case purge the keylist 1444 * and regenerate it later. 1445 */ 1446 if (peer->kpoll != oldpoll) 1447 key_expire(peer); |
1448#endif /* OPENSSL */ |
1449#ifdef DEBUG 1450 if (debug > 1) 1451 printf("poll_update: at %lu %s flags %04x poll %d burst %d last %lu next %lu\n", 1452 current_time, ntoa(&peer->srcadr), peer->flags, 1453 peer->kpoll, peer->burst, peer->outdate, 1454 peer->nextdate); 1455#endif 1456} 1457 1458 1459/* 1460 * clear - clear peer filter registers. See Section 3.4.8 of the spec. 1461 */ 1462void 1463peer_clear( |
1464 struct peer *peer, /* peer structure */ 1465 char *ident /* tally lights */ |
1466 ) 1467{ |
1468 u_char oreach, i; |
1469 1470 /* 1471 * If cryptographic credentials have been acquired, toss them to 1472 * Valhalla. Note that autokeys are ephemeral, in that they are 1473 * tossed immediately upon use. Therefore, the keylist can be 1474 * purged anytime without needing to preserve random keys. Note 1475 * that, if the peer is purged, the cryptographic variables are 1476 * purged, too. This makes it much harder to sneak in some 1477 * unauthenticated data in the clock filter. 1478 */ |
1479 oreach = peer->reach; 1480#ifdef OPENSSL |
1481 key_expire(peer); |
1482 if (peer->pkey != NULL) 1483 EVP_PKEY_free(peer->pkey); 1484 if (peer->ident_pkey != NULL) 1485 EVP_PKEY_free(peer->ident_pkey); 1486 if (peer->subject != NULL) 1487 free(peer->subject); 1488 if (peer->issuer != NULL) 1489 free(peer->issuer); 1490 if (peer->iffval != NULL) 1491 BN_free(peer->iffval); 1492 if (peer->grpkey != NULL) 1493 BN_free(peer->grpkey); 1494 if (peer->cmmd != NULL) 1495 free(peer->cmmd); 1496 value_free(&peer->cookval); 1497 value_free(&peer->recval); 1498 value_free(&peer->tai_leap); 1499 value_free(&peer->encrypt); 1500 value_free(&peer->sndval); 1501#endif /* OPENSSL */ |
1502 1503 /* |
1504 * Wipe the association clean and initialize the nonzero values. |
1505 */ |
1506 memset(CLEAR_TO_ZERO(peer), 0, LEN_CLEAR_TO_ZERO); 1507 if (peer == sys_peer) 1508 sys_peer = NULL; |
1509 peer->estbdelay = sys_bdelay; 1510 peer->hpoll = peer->kpoll = peer->minpoll; 1511 peer->ppoll = peer->maxpoll; |
1512 peer->jitter = MAXDISPERSE; 1513 peer->epoch = current_time; 1514#ifdef REFCLOCK 1515 if (!(peer->flags & FLAG_REFCLOCK)) { 1516 peer->leap = LEAP_NOTINSYNC; 1517 peer->stratum = STRATUM_UNSPEC; |
1518 memcpy(&peer->refid, ident, 4); |
1519 } |
1520#else 1521 peer->leap = LEAP_NOTINSYNC; 1522 peer->stratum = STRATUM_UNSPEC; 1523 memcpy(&peer->refid, ident, 4); |
1524#endif 1525 for (i = 0; i < NTP_SHIFT; i++) { 1526 peer->filter_order[i] = i; 1527 peer->filter_disp[i] = MAXDISPERSE; 1528 peer->filter_epoch[i] = current_time; 1529 } 1530 1531 /* |
1532 * If he dies as a broadcast client, he comes back to life as 1533 * a broadcast client in client mode in order to recover the 1534 * initial autokey values. |
1535 */ |
1536 if (peer->cast_flags & MDF_BCLNT) { 1537 peer->flags |= FLAG_MCAST; 1538 peer->hmode = MODE_CLIENT; 1539 } 1540 1541 /* 1542 * Randomize the first poll to avoid bunching, but only if the 1543 * rascal has never been heard. During initialization use the 1544 * association count to spread out the polls at one-second 1545 * intervals. 1546 */ 1547 peer->nextdate = peer->update = peer->outdate = current_time; 1548 peer->burst = 0; 1549 if (oreach) 1550 poll_update(peer, 0); 1551 else if (initializing) 1552 peer->nextdate = current_time + peer_associations; 1553 else 1554 peer->nextdate = current_time + (u_int)RANDOM % 1555 peer_associations; 1556#ifdef DEBUG 1557 if (debug) 1558 printf("peer_clear: at %ld assoc ID %d refid %s\n", 1559 current_time, peer->associd, ident); 1560#endif |
1561} 1562 1563 1564/* 1565 * clock_filter - add incoming clock sample to filter register and run 1566 * the filter procedure to find the best sample. 1567 */ 1568void 1569clock_filter( |
1570 struct peer *peer, /* peer structure pointer */ 1571 double sample_offset, /* clock offset */ 1572 double sample_delay, /* roundtrip delay */ 1573 double sample_disp /* dispersion */ |
1574 ) 1575{ |
1576 double dst[NTP_SHIFT]; /* distance vector */ 1577 int ord[NTP_SHIFT]; /* index vector */ 1578 int i, j, k, m; 1579 double dsp, jit, dtemp, etemp; |
1580 1581 /* 1582 * Shift the new sample into the register and discard the oldest 1583 * one. The new offset and delay come directly from the 1584 * timestamp calculations. The dispersion grows from the last 1585 * outbound packet or reference clock update to the present time 1586 * and increased by the sum of the peer precision and the system 1587 * precision. The delay can sometimes swing negative due to 1588 * frequency skew, so it is clamped non-negative. 1589 */ 1590 dsp = min(LOGTOD(peer->precision) + LOGTOD(sys_precision) + 1591 sample_disp, MAXDISPERSE); 1592 j = peer->filter_nextpt; 1593 peer->filter_offset[j] = sample_offset; 1594 peer->filter_delay[j] = max(0, sample_delay); 1595 peer->filter_disp[j] = dsp; |
1596 j++; j %= NTP_SHIFT; 1597 peer->filter_nextpt = (u_short) j; |
1598 1599 /* 1600 * Update dispersions since the last update and at the same 1601 * time initialize the distance and index lists. The distance 1602 * list uses a compound metric. If the sample is valid and 1603 * younger than the minimum Allan intercept, use delay; 1604 * otherwise, use biased dispersion. 1605 */ 1606 dtemp = clock_phi * (current_time - peer->update); 1607 peer->update = current_time; 1608 for (i = NTP_SHIFT - 1; i >= 0; i--) { |
1609 if (i != 0) |
1610 peer->filter_disp[j] += dtemp; |
1611 if (peer->filter_disp[j] >= MAXDISPERSE) 1612 peer->filter_disp[j] = MAXDISPERSE; |
1613 if (peer->filter_disp[j] >= MAXDISPERSE) 1614 dst[i] = MAXDISPERSE; 1615 else if (peer->update - peer->filter_epoch[j] > 1616 allan_xpt) 1617 dst[i] = MAXDISTANCE + peer->filter_disp[j]; 1618 else |
1619 dst[i] = peer->filter_delay[j]; |
1620 ord[i] = j; 1621 j++; j %= NTP_SHIFT; 1622 } |
1623 peer->filter_epoch[j] = current_time; |
1624 1625 /* 1626 * Sort the samples in both lists by distance. 1627 */ 1628 for (i = 1; i < NTP_SHIFT; i++) { 1629 for (j = 0; j < i; j++) { 1630 if (dst[j] > dst[i]) { 1631 k = ord[j]; --- 9 unchanged lines hidden (view full) --- 1641 /* 1642 * Copy the index list to the association structure so ntpq 1643 * can see it later. Prune the distance list to samples less 1644 * than MAXDISTANCE, but keep at least two valid samples for 1645 * jitter calculation. 1646 */ 1647 m = 0; 1648 for (i = 0; i < NTP_SHIFT; i++) { |
1649 peer->filter_order[i] = (u_char) ord[i]; |
1650 if (dst[i] >= MAXDISPERSE || (m >= 2 && dst[i] >= 1651 MAXDISTANCE)) 1652 continue; 1653 m++; 1654 } 1655 1656 /* 1657 * Compute the dispersion and jitter squares. The dispersion 1658 * is weighted exponentially by NTP_FWEIGHT (0.5) so it is 1659 * normalized close to 1.0. The jitter is the mean of the square 1660 * differences relative to the lowest delay sample. If no 1661 * acceptable samples remain in the shift register, quietly |
1662 * tiptoe home leaving only the dispersion. |
1663 */ 1664 jit = 0; 1665 peer->disp = 0; 1666 k = ord[0]; 1667 for (i = NTP_SHIFT - 1; i >= 0; i--) { 1668 1669 j = ord[i]; 1670 peer->disp = NTP_FWEIGHT * (peer->disp + --- 6 unchanged lines hidden (view full) --- 1677 /* 1678 * If no acceptable samples remain in the shift register, 1679 * quietly tiptoe home leaving only the dispersion. Otherwise, 1680 * save the offset, delay and jitter average. Note the jitter 1681 * must not be less than the system precision. 1682 */ 1683 if (m == 0) 1684 return; |
1685 etemp = fabs(peer->offset - peer->filter_offset[k]); 1686 dtemp = sqrt(peer->jitter); |
1687 peer->offset = peer->filter_offset[k]; 1688 peer->delay = peer->filter_delay[k]; 1689 if (m > 1) 1690 jit /= m - 1; 1691 peer->jitter = max(jit, SQUARE(LOGTOD(sys_precision))); 1692 1693 /* 1694 * A new sample is useful only if it is younger than the last |
1695 * one used, but only if the sucker has been synchronized. |
1696 */ |
1697 if (peer->filter_epoch[k] <= peer->epoch && sys_leap != 1698 LEAP_NOTINSYNC) { |
1699#ifdef DEBUG 1700 if (debug) 1701 printf("clock_filter: discard %lu\n", 1702 peer->epoch - peer->filter_epoch[k]); 1703#endif 1704 return; 1705 } 1706 1707 /* 1708 * If the difference between the last offset and the current one |
1709 * exceeds the jitter by CLOCK_SGATE and the interval since the 1710 * last update is less than twice the system poll interval, |
1711 * consider the update a popcorn spike and ignore it. 1712 */ |
1713 if (m > 1 && etemp > CLOCK_SGATE * dtemp && 1714 (long)(peer->filter_epoch[k] - peer->epoch) < (1 << (sys_poll + 1715 1))) { |
1716#ifdef DEBUG 1717 if (debug) |
1718 printf("clock_filter: popcorn %.6f %.6f\n", 1719 etemp, dtemp); |
1720#endif 1721 return; 1722 } 1723 1724 /* 1725 * The mitigated sample statistics are saved for later |
1726 * processing. |
1727 */ 1728 peer->epoch = peer->filter_epoch[k]; |
1729#ifdef DEBUG 1730 if (debug) 1731 printf( 1732 "clock_filter: n %d off %.6f del %.6f dsp %.6f jit %.6f, age %lu\n", 1733 m, peer->offset, peer->delay, peer->disp, 1734 SQRT(peer->jitter), peer->update - peer->epoch); 1735#endif 1736} 1737 1738 1739/* 1740 * clock_select - find the pick-of-the-litter clock |
1741 * 1742 * LOCKCLOCK: If the local clock is the prefer peer, it will always be 1743 * enabled, even if declared falseticker, (2) only the prefer peer can 1744 * be selected as the system peer, (3) if the external source is down, 1745 * the system leap bits are set to 11 and the stratum set to infinity. |
1746 */ 1747void 1748clock_select(void) 1749{ |
1750 struct peer *peer; 1751 int i, j, k, n; 1752 int nlist, nl3; 1753 1754 double d, e, f; 1755 int allow, sw, osurv; 1756 double high, low; 1757 double synch[NTP_MAXCLOCK], error[NTP_MAXCLOCK]; |
1758 struct peer *osys_peer; 1759 struct peer *typeacts = NULL; 1760 struct peer *typelocal = NULL; 1761 struct peer *typepps = NULL; 1762 struct peer *typesystem = NULL; 1763 1764 static int list_alloc = 0; 1765 static struct endpoint *endpoint = NULL; --- 4 unchanged lines hidden (view full) --- 1770 static u_int peer_list_size = 0; 1771 1772 /* 1773 * Initialize and create endpoint, index and peer lists big 1774 * enough to handle all associations. 1775 */ 1776 osys_peer = sys_peer; 1777 sys_peer = NULL; |
1778 osurv = sys_survivors; 1779 sys_survivors = 0; |
1780 sys_prefer = NULL; |
1781#ifdef LOCKCLOCK 1782 sys_leap = LEAP_NOTINSYNC; 1783 sys_stratum = STRATUM_UNSPEC; 1784 memcpy(&sys_refid, "DOWN", 4); 1785#endif /* LOCKCLOCK */ 1786 nlist = 0; |
1787 for (n = 0; n < HASH_SIZE; n++) 1788 nlist += peer_hash_count[n]; 1789 if (nlist > list_alloc) { 1790 if (list_alloc > 0) { 1791 free(endpoint); 1792 free(indx); 1793 free(peer_list); 1794 } 1795 while (list_alloc < nlist) { 1796 list_alloc += 5; 1797 endpoint_size += 5 * 3 * sizeof(*endpoint); 1798 indx_size += 5 * 3 * sizeof(*indx); 1799 peer_list_size += 5 * sizeof(*peer_list); 1800 } |
1801 endpoint = emalloc(endpoint_size); 1802 indx = emalloc(indx_size); 1803 peer_list = emalloc(peer_list_size); |
1804 } 1805 1806 /* 1807 * Initially, we populate the island with all the rifraff peers 1808 * that happen to be lying around. Those with seriously 1809 * defective clocks are immediately booted off the island. Then, 1810 * the falsetickers are culled and put to sea. The truechimers 1811 * remaining are subject to repeated rounds where the most 1812 * unpopular at each round is kicked off. When the population |
1813 * has dwindled to sys_minclock, the survivors split a million 1814 * bucks and collectively crank the chimes. |
1815 */ 1816 nlist = nl3 = 0; /* none yet */ 1817 for (n = 0; n < HASH_SIZE; n++) { 1818 for (peer = peer_hash[n]; peer != NULL; peer = 1819 peer->next) { 1820 peer->flags &= ~FLAG_SYSPEER; 1821 peer->status = CTL_PST_SEL_REJECT; 1822 1823 /* |
1824 * Leave the island immediately if the peer is 1825 * unfit to synchronize. 1826 */ 1827 if (peer_unfit(peer)) |
1828 continue; 1829 1830 /* 1831 * Don't allow the local clock or modem drivers 1832 * in the kitchen at this point, unless the 1833 * prefer peer. Do that later, but only if 1834 * nobody else is around. These guys are all 1835 * configured, so we never throw them away. 1836 */ 1837 if (peer->refclktype == REFCLK_LOCALCLOCK 1838#if defined(VMS) && defined(VMS_LOCALUNIT) |
1839 /* wjm: VMS_LOCALUNIT taken seriously */ 1840 && REFCLOCKUNIT(&peer->srcadr) != 1841 VMS_LOCALUNIT |
1842#endif /* VMS && VMS_LOCALUNIT */ 1843 ) { 1844 typelocal = peer; 1845 if (!(peer->flags & FLAG_PREFER)) 1846 continue; /* no local clock */ |
1847#ifdef LOCKCLOCK 1848 else 1849 sys_prefer = peer; 1850#endif /* LOCKCLOCK */ |
1851 } 1852 if (peer->sstclktype == CTL_SST_TS_TELEPHONE) { 1853 typeacts = peer; 1854 if (!(peer->flags & FLAG_PREFER)) 1855 continue; /* no acts */ 1856 } 1857 1858 /* 1859 * If we get this far, the peer can stay on the 1860 * island, but does not yet have the immunity 1861 * idol. 1862 */ |
1863 peer->status = CTL_PST_SEL_SANE; 1864 peer_list[nlist++] = peer; 1865 1866 /* 1867 * Insert each interval endpoint on the sorted 1868 * list. 1869 */ 1870 e = peer->offset; /* Upper end */ --- 4 unchanged lines hidden (view full) --- 1875 break; 1876 indx[i + 3] = indx[i]; 1877 } 1878 indx[i + 3] = nl3; 1879 endpoint[nl3].type = 1; 1880 endpoint[nl3++].val = e; 1881 1882 e = e - f; /* Center point */ |
1883 for (; i >= 0; i--) { |
1884 if (e >= endpoint[indx[i]].val) 1885 break; 1886 indx[i + 2] = indx[i]; 1887 } 1888 indx[i + 2] = nl3; 1889 endpoint[nl3].type = 0; 1890 endpoint[nl3++].val = e; 1891 1892 e = e - f; /* Lower end */ |
1893 for (; i >= 0; i--) { |
1894 if (e >= endpoint[indx[i]].val) 1895 break; 1896 indx[i + 1] = indx[i]; 1897 } 1898 indx[i + 1] = nl3; 1899 endpoint[nl3].type = -1; 1900 endpoint[nl3++].val = e; 1901 } 1902 } 1903#ifdef DEBUG 1904 if (debug > 2) 1905 for (i = 0; i < nl3; i++) 1906 printf("select: endpoint %2d %.6f\n", 1907 endpoint[indx[i]].type, 1908 endpoint[indx[i]].val); 1909#endif |
1910 /* 1911 * This is the actual algorithm that cleaves the truechimers 1912 * from the falsetickers. The original algorithm was described 1913 * in Keith Marzullo's dissertation, but has been modified for 1914 * better accuracy. 1915 * 1916 * Briefly put, we first assume there are no falsetickers, then 1917 * scan the candidate list first from the low end upwards and 1918 * then from the high end downwards. The scans stop when the 1919 * number of intersections equals the number of candidates less 1920 * the number of falsetickers. If this doesn't happen for a 1921 * given number of falsetickers, we bump the number of 1922 * falsetickers and try again. If the number of falsetickers 1923 * becomes equal to or greater than half the number of 1924 * candidates, the Albanians have won the Byzantine wars and 1925 * correct synchronization is not possible. 1926 * 1927 * Here, nlist is the number of candidates and allow is the 1928 * number of falsetickers. 1929 */ 1930 low = 1e9; 1931 high = -1e9; 1932 for (allow = 0; 2 * allow < nlist; allow++) { 1933 int found; 1934 1935 /* 1936 * Bound the interval (low, high) as the largest 1937 * interval containing points from presumed truechimers. 1938 */ 1939 found = 0; 1940 n = 0; 1941 for (i = 0; i < nl3; i++) { 1942 low = endpoint[indx[i]].val; 1943 n -= endpoint[indx[i]].type; 1944 if (n >= nlist - allow) |
1945 break; 1946 if (endpoint[indx[i]].type == 0) 1947 found++; 1948 } |
1949 n = 0; 1950 for (j = nl3 - 1; j >= 0; j--) { 1951 high = endpoint[indx[j]].val; |
1952 n += endpoint[indx[j]].type; |
1953 if (n >= nlist - allow) |
1954 break; 1955 if (endpoint[indx[j]].type == 0) 1956 found++; 1957 } |
1958 1959 /* 1960 * If the number of candidates found outside the 1961 * interval is greater than the number of falsetickers, 1962 * then at least one truechimer is outside the interval, 1963 * so go around again. This is what makes this algorithm 1964 * different than Marzullo's. 1965 */ |
1966 if (found > allow) |
1967 continue; 1968 1969 /* 1970 * If an interval containing truechimers is found, stop. 1971 * If not, increase the number of falsetickers and go 1972 * around again. 1973 */ 1974 if (high > low) |
1975 break; |
1976 } 1977 1978 /* 1979 * If no survivors remain at this point, check if the local 1980 * clock or modem drivers have been found. If so, nominate one |
1981 * of them as the only survivor. Otherwise, give up and leave 1982 * the island to the rats. |
1983 */ |
1984 if (high <= low) { |
1985 if (typeacts != 0) { 1986 typeacts->status = CTL_PST_SEL_SANE; 1987 peer_list[0] = typeacts; 1988 nlist = 1; 1989 } else if (typelocal != 0) { 1990 typelocal->status = CTL_PST_SEL_SANE; 1991 peer_list[0] = typelocal; 1992 nlist = 1; 1993 } else { 1994 if (osys_peer != NULL) { 1995 sys_poll = NTP_MINPOLL; 1996 NLOG(NLOG_SYNCSTATUS) 1997 msyslog(LOG_INFO, |
1998 "no servers reachable"); 1999 report_event(EVNT_PEERSTCHG, NULL); |
2000 } |
2001 if (osurv > 0) 2002 resetmanycast(); |
2003 return; 2004 } 2005 } |
2006 2007 /* |
2008 * We can only trust the survivors if the number of candidates 2009 * sys_minsane is at least the number required to detect and 2010 * cast out one falsticker. For the Byzantine agreement 2011 * algorithm used here, that number is 4; however, the default 2012 * sys_minsane is 1 to speed initial synchronization. Careful 2013 * operators will tinker the value to 4 and use at least that 2014 * number of synchronization sources. 2015 */ 2016 if (nlist < sys_minsane) 2017 return; 2018 2019 /* |
2020 * Clustering algorithm. Construct candidate list in order first |
2021 * by stratum then by root distance, but keep only the best 2022 * NTP_MAXCLOCK of them. Scan the list to find falsetickers, who 2023 * leave the island immediately. If a falseticker is not 2024 * configured, his association raft is drowned as well, but only 2025 * if at at least eight poll intervals have gone. We must leave 2026 * at least one peer to collect the million bucks. 2027 * 2028 * Note the hysteresis gimmick that increases the effective 2029 * distance for those rascals that have not made the final cut. 2030 * This is to discourage clockhopping. Note also the prejudice 2031 * against lower stratum peers if the floor is elevated. |
2032 */ 2033 j = 0; 2034 for (i = 0; i < nlist; i++) { 2035 peer = peer_list[i]; |
2036 if (nlist > 1 && (peer->offset <= low || peer->offset >= |
2037 high)) { 2038 if (!(peer->flags & FLAG_CONFIG)) 2039 unpeer(peer); 2040 continue; 2041 } 2042 peer->status = CTL_PST_SEL_DISTSYSPEER; |
2043 d = peer->stratum; 2044 if (d < sys_floor) 2045 d += sys_floor; 2046 if (d > sys_ceiling) 2047 d = STRATUM_UNSPEC; 2048 d = root_distance(peer) + d * MAXDISTANCE; 2049 d *= 1. - peer->hyst; |
2050 if (j >= NTP_MAXCLOCK) { 2051 if (d >= synch[j - 1]) 2052 continue; 2053 else 2054 j--; 2055 } 2056 for (k = j; k > 0; k--) { 2057 if (d >= synch[k - 1]) 2058 break; 2059 peer_list[k] = peer_list[k - 1]; 2060 error[k] = error[k - 1]; 2061 synch[k] = synch[k - 1]; 2062 } 2063 peer_list[k] = peer; 2064 error[k] = peer->jitter; 2065 synch[k] = d; 2066 j++; 2067 } 2068 nlist = j; |
2069 if (nlist == 0) { 2070#ifdef DEBUG 2071 if (debug) 2072 printf("clock_select: empty intersection interval\n"); 2073#endif 2074 return; 2075 } |
2076 for (i = 0; i < nlist; i++) { 2077 peer_list[i]->status = CTL_PST_SEL_SELCAND; 2078 2079#ifdef DEBUG 2080 if (debug > 2) |
2081 printf("select: %s distance %.6f jitter %.6f\n", 2082 ntoa(&peer_list[i]->srcadr), synch[i], 2083 SQRT(error[i])); |
2084#endif 2085 } 2086 2087 /* 2088 * Now, vote outlyers off the island by select jitter weighted 2089 * by root dispersion. Continue voting as long as there are more |
2090 * than sys_minclock survivors and the minimum select jitter |
2091 * squared is greater than the maximum peer jitter squared. Stop 2092 * if we are about to discard a prefer peer, who of course has 2093 * the immunity idol. 2094 */ 2095 while (1) { 2096 d = 1e9; 2097 e = -1e9; 2098 k = 0; 2099 for (i = 0; i < nlist; i++) { |
2100 if (error[i] < d) 2101 d = error[i]; 2102 f = 0; 2103 if (nlist > 1) { 2104 for (j = 0; j < nlist; j++) 2105 f += DIFF(peer_list[j]->offset, 2106 peer_list[i]->offset); 2107 f /= nlist - 1; 2108 } |
2109 if (f * synch[i] > e) { 2110 sys_selerr = f; 2111 e = f * synch[i]; 2112 k = i; 2113 } 2114 } |
2115 f = max(sys_selerr, SQUARE(LOGTOD(sys_precision))); 2116 if (nlist <= sys_minclock || f <= d || 2117 peer_list[k]->flags & FLAG_PREFER) 2118 break; |
2119#ifdef DEBUG 2120 if (debug > 2) 2121 printf( |
2122 "select: drop %s select %.6f jitter %.6f\n", 2123 ntoa(&peer_list[k]->srcadr), 2124 SQRT(sys_selerr), SQRT(d)); |
2125#endif |
2126 if (!(peer_list[k]->flags & FLAG_CONFIG) && 2127 peer_list[k]->hmode == MODE_CLIENT) |
2128 unpeer(peer_list[k]); 2129 for (j = k + 1; j < nlist; j++) { 2130 peer_list[j - 1] = peer_list[j]; 2131 error[j - 1] = error[j]; 2132 } 2133 nlist--; 2134 } 2135 |
2136 /* |
2137 * What remains is a list usually not greater than sys_minclock |
2138 * peers. We want only a peer at the lowest stratum to become 2139 * the system peer, although all survivors are eligible for the 2140 * combining algorithm. First record their order, diddle the |
2141 * flags and clamp the poll intervals. Then, consider each peer 2142 * in turn and OR the leap bits on the assumption that, if some 2143 * of them honk nonzero bits, they must know what they are 2144 * doing. Check for prefer and pps peers at any stratum. Check 2145 * if the old system peer is among the peers at the lowest 2146 * stratum. Note that the head of the list is at the lowest |
2147 * stratum and that unsynchronized peers cannot survive this 2148 * far. 2149 * |
2150 * Fiddle for hysteresis. Pump it up for a peer only if the peer 2151 * stratum is at least the floor and there are enough survivors. 2152 * This minimizes the pain when tossing out rascals beneath the 2153 * floorboard. Don't count peers with stratum above the ceiling. 2154 * Manycast is sooo complicated. |
2155 */ |
2156 leap_consensus = 0; 2157 for (i = nlist - 1; i >= 0; i--) { 2158 peer = peer_list[i]; |
2159 leap_consensus |= peer->leap; |
2160 peer->status = CTL_PST_SEL_SYNCCAND; |
2161 peer->rank++; |
2162 peer->flags |= FLAG_SYSPEER; |
2163 if (peer->stratum >= sys_floor && osurv >= sys_minclock) 2164 peer->hyst = HYST; 2165 else 2166 peer->hyst = 0; 2167 if (peer->stratum <= sys_ceiling) 2168 sys_survivors++; 2169 if (peer->flags & FLAG_PREFER) 2170 sys_prefer = peer; 2171 if (peer->refclktype == REFCLK_ATOM_PPS && 2172 peer->stratum < STRATUM_UNSPEC) 2173 typepps = peer; 2174 if (peer->stratum == peer_list[0]->stratum && peer == 2175 osys_peer) 2176 typesystem = peer; |
2177 } 2178 2179 /* |
2180 * In manycast client mode we may have spooked a sizeable number 2181 * of peers that we don't need. If there are at least 2182 * sys_minclock of them, the manycast message will be turned 2183 * off. By the time we get here we nay be ready to prune some of 2184 * them back, but we want to make sure all the candicates have 2185 * had a chance. If they didn't pass the sanity and intersection 2186 * tests, they have already been voted off the island. 2187 */ 2188 if (sys_survivors < sys_minclock && osurv >= sys_minclock) 2189 resetmanycast(); 2190 2191 /* |
2192 * Mitigation rules of the game. There are several types of 2193 * peers that make a difference here: (1) prefer local peers 2194 * (type REFCLK_LOCALCLOCK with FLAG_PREFER) or prefer modem 2195 * peers (type REFCLK_NIST_ATOM etc with FLAG_PREFER), (2) pps 2196 * peers (type REFCLK_ATOM_PPS), (3) remaining prefer peers 2197 * (flag FLAG_PREFER), (4) the existing system peer, if any, (5) 2198 * the head of the survivor list. Note that only one peer can be 2199 * declared prefer. The order of preference is in the order --- 11 unchanged lines hidden (view full) --- 2211 sys_peer->status = CTL_PST_SEL_SYSPEER; 2212 sys_offset = sys_peer->offset; 2213 sys_syserr = sys_peer->jitter; 2214#ifdef DEBUG 2215 if (debug > 1) 2216 printf("select: prefer offset %.6f\n", 2217 sys_offset); 2218#endif |
2219 } 2220#ifndef LOCKCLOCK 2221 else if (typepps) { |
2222 sys_peer = typepps; 2223 sys_peer->status = CTL_PST_SEL_PPS; 2224 sys_offset = sys_peer->offset; 2225 sys_syserr = sys_peer->jitter; 2226 if (!pps_control) 2227 NLOG(NLOG_SYSEVENT) |
2228 msyslog(LOG_INFO, "pps sync enabled"); |
2229 pps_control = current_time; 2230#ifdef DEBUG 2231 if (debug > 1) 2232 printf("select: pps offset %.6f\n", 2233 sys_offset); 2234#endif 2235 } else { 2236 if (typesystem) 2237 sys_peer = osys_peer; 2238 else 2239 sys_peer = peer_list[0]; 2240 sys_peer->status = CTL_PST_SEL_SYSPEER; |
2241 sys_peer->rank++; |
2242 sys_offset = clock_combine(peer_list, nlist); 2243 sys_syserr = sys_peer->jitter + sys_selerr; 2244#ifdef DEBUG 2245 if (debug > 1) 2246 printf("select: combine offset %.6f\n", 2247 sys_offset); 2248#endif 2249 } |
2250#endif /* LOCKCLOCK */ 2251 if (osys_peer != sys_peer) { 2252 char *src; 2253 2254 if (sys_peer == NULL) 2255 sys_peer_refid = 0; 2256 else 2257 sys_peer_refid = addr2refid(&sys_peer->srcadr); 2258 report_event(EVNT_PEERSTCHG, NULL); 2259 2260#ifdef REFCLOCK 2261 if (ISREFCLOCKADR(&sys_peer->srcadr)) 2262 src = refnumtoa(&sys_peer->srcadr); 2263 else 2264#endif 2265 src = ntoa(&sys_peer->srcadr); 2266 NLOG(NLOG_SYNCSTATUS) 2267 msyslog(LOG_INFO, "synchronized to %s, stratum=%d", src, 2268 sys_peer->stratum); 2269 } |
2270 clock_update(); 2271} 2272 2273/* 2274 * clock_combine - combine offsets from selected peers 2275 */ 2276static double 2277clock_combine( 2278 struct peer **peers, |
2279 int npeers |
2280 ) 2281{ |
2282 int i; 2283 double x, y, z; 2284 |
2285 y = z = 0; 2286 for (i = 0; i < npeers; i++) { 2287 x = root_distance(peers[i]); 2288 y += 1. / x; 2289 z += peers[i]->offset / x; 2290 } 2291 return (z / y); 2292} --- 20 unchanged lines hidden (view full) --- 2313 * peer_xmit - send packet for persistent association. 2314 */ 2315static void 2316peer_xmit( 2317 struct peer *peer /* peer structure pointer */ 2318 ) 2319{ 2320 struct pkt xpkt; /* transmit packet */ |
2321 int sendlen, authlen; 2322 keyid_t xkeyid = 0; /* transmit key ID */ 2323 l_fp xmt_tx; |
2324 2325 /* 2326 * Initialize transmit packet header fields. 2327 */ 2328 xpkt.li_vn_mode = PKT_LI_VN_MODE(sys_leap, peer->version, 2329 peer->hmode); 2330 xpkt.stratum = STRATUM_TO_PKT(sys_stratum); 2331 xpkt.ppoll = peer->hpoll; --- 14 unchanged lines hidden (view full) --- 2346 * until after receiving a packet and setting the right 2347 * interface. So, the first packet goes out unauthenticated. 2348 * That's why the really icky test next is here. 2349 */ 2350 sendlen = LEN_PKT_NOMAC; 2351 if (!(peer->flags & FLAG_AUTHENABLE)) { 2352 get_systime(&peer->xmt); 2353 HTONL_FP(&peer->xmt, &xpkt.xmt); |
2354 sendpkt(&peer->srcadr, peer->dstadr, sys_ttl[peer->ttl], 2355 &xpkt, sendlen); |
2356 peer->sent++; 2357#ifdef DEBUG 2358 if (debug) 2359 printf("transmit: at %ld %s->%s mode %d\n", |
2360 current_time, stoa(&peer->dstadr->sin), 2361 stoa(&peer->srcadr), peer->hmode); |
2362#endif 2363 return; 2364 } 2365 2366 /* 2367 * The received packet contains a MAC, so the transmitted packet 2368 * must be authenticated. If autokey is enabled, fuss with the 2369 * various modes; otherwise, private key cryptography is used. 2370 */ |
2371#ifdef OPENSSL 2372 if (crypto_flags && (peer->flags & FLAG_SKEY)) { 2373 struct exten *exten; /* extension field */ 2374 u_int opcode; |
2375 2376 /* 2377 * The Public Key Dance (PKD): Cryptographic credentials 2378 * are contained in extension fields, each including a 2379 * 4-octet length/code word followed by a 4-octet 2380 * association ID and optional additional data. Optional 2381 * data includes a 4-octet data length field followed by 2382 * the data itself. Request messages are sent from a --- 43 unchanged lines hidden (view full) --- 2426 break; 2427 else 2428 key_expire(peer); 2429 } 2430 peer->keyid = xkeyid; 2431 switch (peer->hmode) { 2432 2433 /* |
2434 * In broadcast server mode the autokey values are 2435 * required by the broadcast clients. Push them when a 2436 * new keylist is generated; otherwise, push the 2437 * association message so the client can request them at 2438 * other times. |
2439 */ 2440 case MODE_BROADCAST: 2441 if (peer->flags & FLAG_ASSOC) |
2442 exten = crypto_args(peer, CRYPTO_AUTO | 2443 CRYPTO_RESP, NULL); |
2444 else |
2445 exten = crypto_args(peer, CRYPTO_ASSOC | 2446 CRYPTO_RESP, NULL); 2447 sendlen += crypto_xmit(&xpkt, &peer->srcadr, 2448 sendlen, exten, 0); 2449 free(exten); |
2450 break; 2451 2452 /* |
2453 * In symmetric modes the digest, certificate, agreement 2454 * parameters, cookie and autokey values are required. 2455 * The leapsecond table is optional. But, a passive peer 2456 * will not believe the active peer until the latter has 2457 * synchronized, so the agreement must be postponed 2458 * until then. In any case, if a new keylist is 2459 * generated, the autokey values are pushed. |
2460 */ 2461 case MODE_ACTIVE: 2462 case MODE_PASSIVE: |
2463 if (peer->cmmd != NULL) { 2464 peer->cmmd->associd = 2465 htonl(peer->associd); 2466 sendlen += crypto_xmit(&xpkt, 2467 &peer->srcadr, sendlen, peer->cmmd, 2468 0); 2469 free(peer->cmmd); 2470 peer->cmmd = NULL; 2471 } 2472 exten = NULL; |
2473 if (!peer->crypto) |
2474 exten = crypto_args(peer, CRYPTO_ASSOC, 2475 sys_hostname); 2476 else if (!(peer->crypto & CRYPTO_FLAG_VALID)) 2477 exten = crypto_args(peer, CRYPTO_CERT, 2478 peer->issuer); 2479 2480 /* 2481 * Identity. Note we have to sign the 2482 * certificate before the cookie to avoid a 2483 * deadlock when the passive peer is walking the 2484 * certificate trail. Awesome. 2485 */ 2486 else if ((opcode = crypto_ident(peer)) != 0) 2487 exten = crypto_args(peer, opcode, NULL); 2488 else if (sys_leap != LEAP_NOTINSYNC && 2489 !(peer->crypto & CRYPTO_FLAG_SIGN)) 2490 exten = crypto_args(peer, CRYPTO_SIGN, 2491 sys_hostname); 2492 2493 /* 2494 * Autokey. We request the cookie only when the 2495 * server and client are synchronized and 2496 * signatures work both ways. On the other hand, 2497 * the active peer needs the autokey values 2498 * before then and when the passive peer is 2499 * waiting for the active peer to synchronize. 2500 * Any time we regenerate the key list, we offer 2501 * the autokey values without being asked. 2502 */ 2503 else if (sys_leap != LEAP_NOTINSYNC && 2504 peer->leap != LEAP_NOTINSYNC && 2505 !(peer->crypto & CRYPTO_FLAG_AGREE)) 2506 exten = crypto_args(peer, CRYPTO_COOK, 2507 NULL); 2508 else if (peer->flags & FLAG_ASSOC) 2509 exten = crypto_args(peer, CRYPTO_AUTO | 2510 CRYPTO_RESP, NULL); 2511 else if (!(peer->crypto & CRYPTO_FLAG_AUTO)) 2512 exten = crypto_args(peer, CRYPTO_AUTO, 2513 NULL); 2514 2515 /* 2516 * Postamble. We trade leapseconds only when the 2517 * server and client are synchronized. 2518 */ 2519 else if (sys_leap != LEAP_NOTINSYNC && 2520 peer->leap != LEAP_NOTINSYNC && 2521 peer->crypto & CRYPTO_FLAG_TAI && 2522 !(peer->crypto & CRYPTO_FLAG_LEAP)) 2523 exten = crypto_args(peer, CRYPTO_TAI, 2524 NULL); 2525 if (exten != NULL) { 2526 sendlen += crypto_xmit(&xpkt, 2527 &peer->srcadr, sendlen, exten, 0); 2528 free(exten); 2529 } |
2530 break; 2531 2532 /* |
2533 * In client mode the digest, certificate, agreement 2534 * parameters and cookie are required. The leapsecond 2535 * table is optional. If broadcast client mode, the 2536 * autokey values are required as well. In broadcast 2537 * client mode, these values must be acquired during the |
2538 * client/server exchange to avoid having to wait until 2539 * the next key list regeneration. Otherwise, the poor 2540 * dude may die a lingering death until becoming |
2541 * unreachable and attempting rebirth. 2542 * 2543 * If neither the server or client have the agreement 2544 * parameters, the protocol transmits the cookie in the 2545 * clear. If the server has the parameters, the client 2546 * requests them and the protocol blinds it using the 2547 * agreed key. It is a protocol error if the client has 2548 * the parameters but the server does not. |
2549 */ 2550 case MODE_CLIENT: |
2551 if (peer->cmmd != NULL) { 2552 peer->cmmd->associd = 2553 htonl(peer->associd); 2554 sendlen += crypto_xmit(&xpkt, 2555 &peer->srcadr, sendlen, peer->cmmd, 2556 0); 2557 free(peer->cmmd); 2558 peer->cmmd = NULL; 2559 } 2560 exten = NULL; |
2561 if (!peer->crypto) |
2562 exten = crypto_args(peer, CRYPTO_ASSOC, 2563 sys_hostname); 2564 else if (!(peer->crypto & CRYPTO_FLAG_VALID)) 2565 exten = crypto_args(peer, CRYPTO_CERT, 2566 peer->issuer); 2567 2568 /* 2569 * Identity. 2570 */ 2571 else if ((opcode = crypto_ident(peer)) != 0) 2572 exten = crypto_args(peer, opcode, NULL); 2573 2574 /* 2575 * Autokey 2576 */ 2577 else if (!(peer->crypto & CRYPTO_FLAG_AGREE)) 2578 exten = crypto_args(peer, CRYPTO_COOK, 2579 NULL); 2580 else if (!(peer->crypto & CRYPTO_FLAG_AUTO) && |
2581 (peer->cast_flags & MDF_BCLNT)) |
2582 exten = crypto_args(peer, CRYPTO_AUTO, 2583 NULL); 2584 2585 /* 2586 * Postamble. We can sign the certificate here, 2587 * since there is no chance of deadlock. 2588 */ 2589 else if (sys_leap != LEAP_NOTINSYNC && 2590 !(peer->crypto & CRYPTO_FLAG_SIGN)) 2591 exten = crypto_args(peer, CRYPTO_SIGN, 2592 sys_hostname); 2593 else if (sys_leap != LEAP_NOTINSYNC && 2594 peer->crypto & CRYPTO_FLAG_TAI && 2595 !(peer->crypto & CRYPTO_FLAG_LEAP)) 2596 exten = crypto_args(peer, CRYPTO_TAI, 2597 NULL); 2598 if (exten != NULL) { 2599 sendlen += crypto_xmit(&xpkt, 2600 &peer->srcadr, sendlen, exten, 0); 2601 free(exten); 2602 } |
2603 break; 2604 } 2605 2606 /* 2607 * If extension fields are present, we must use a |
2608 * private value of zero and force min poll interval. |
2609 * Most intricate. 2610 */ 2611 if (sendlen > LEN_PKT_NOMAC) 2612 session_key(&peer->dstadr->sin, &peer->srcadr, 2613 xkeyid, 0, 2); 2614 } |
2615#endif /* OPENSSL */ |
2616 xkeyid = peer->keyid; 2617 get_systime(&peer->xmt); 2618 L_ADD(&peer->xmt, &sys_authdelay); 2619 HTONL_FP(&peer->xmt, &xpkt.xmt); 2620 authlen = authencrypt(xkeyid, (u_int32 *)&xpkt, sendlen); 2621 if (authlen == 0) { |
2622 msyslog(LOG_INFO, 2623 "transmit: encryption key %d not found", xkeyid); 2624 if (peer->flags & FLAG_CONFIG) 2625 peer_clear(peer, "NKEY"); 2626 else 2627 unpeer(peer); |
2628 return; 2629 } 2630 sendlen += authlen; |
2631#ifdef OPENSSL |
2632 if (xkeyid > NTP_MAXKEY) 2633 authtrust(xkeyid, 0); |
2634#endif /* OPENSSL */ |
2635 get_systime(&xmt_tx); 2636 if (sendlen > sizeof(xpkt)) { 2637 msyslog(LOG_ERR, "buffer overflow %u", sendlen); |
2638 exit (-1); |
2639 } |
2640 sendpkt(&peer->srcadr, peer->dstadr, sys_ttl[peer->ttl], &xpkt, 2641 sendlen); |
2642 2643 /* 2644 * Calculate the encryption delay. Keep the minimum over 2645 * the latest two samples. 2646 */ 2647 L_SUB(&xmt_tx, &peer->xmt); 2648 L_ADD(&xmt_tx, &sys_authdelay); 2649 sys_authdly[1] = sys_authdly[0]; 2650 sys_authdly[0] = xmt_tx.l_uf; 2651 if (sys_authdly[0] < sys_authdly[1]) 2652 sys_authdelay.l_uf = sys_authdly[0]; 2653 else 2654 sys_authdelay.l_uf = sys_authdly[1]; 2655 peer->sent++; |
2656#ifdef OPENSSL |
2657#ifdef DEBUG 2658 if (debug) 2659 printf( 2660 "transmit: at %ld %s->%s mode %d keyid %08x len %d mac %d index %d\n", 2661 current_time, ntoa(&peer->dstadr->sin), |
2662 ntoa(&peer->srcadr), peer->hmode, xkeyid, sendlen - 2663 authlen, authlen, peer->keynumber); |
2664#endif 2665#else 2666#ifdef DEBUG 2667 if (debug) 2668 printf( 2669 "transmit: at %ld %s->%s mode %d keyid %08x len %d mac %d\n", 2670 current_time, ntoa(&peer->dstadr->sin), |
2671 ntoa(&peer->srcadr), peer->hmode, xkeyid, sendlen - 2672 authlen, authlen); |
2673#endif |
2674#endif /* OPENSSL */ |
2675} 2676 2677 2678/* 2679 * fast_xmit - Send packet for nonpersistent association. Note that 2680 * neither the source or destination can be a broadcast address. 2681 */ 2682static void 2683fast_xmit( 2684 struct recvbuf *rbufp, /* receive packet pointer */ |
2685 int xmode, /* transmit mode */ 2686 keyid_t xkeyid, /* transmit key ID */ 2687 int mask /* restrict mask */ |
2688 ) 2689{ |
2690 struct pkt xpkt; /* transmit packet structure */ 2691 struct pkt *rpkt; /* receive packet structure */ 2692 l_fp xmt_ts; /* timestamp */ 2693 l_fp xmt_tx; /* timestamp after authent */ 2694 int sendlen, authlen; 2695#ifdef OPENSSL 2696 u_int32 temp32; 2697#endif |
2698 2699 /* 2700 * Initialize transmit packet header fields from the receive 2701 * buffer provided. We leave some fields intact as received. If 2702 * the gazinta was from a multicast address, the gazouta must go 2703 * out another way. 2704 */ 2705 rpkt = &rbufp->recv_pkt; 2706 if (rbufp->dstadr->flags & INT_MULTICAST) 2707 rbufp->dstadr = findinterface(&rbufp->recv_srcadr); 2708 2709 /* |
2710 * If the packet has picked up a restriction due to either 2711 * access denied or rate exceeded, decide what to do with it. |
2712 */ |
2713 if (mask & (RES_DONTTRUST | RES_LIMITED)) { 2714 char *code = "????"; 2715 2716 if (mask & RES_LIMITED) { 2717 sys_limitrejected++; 2718 code = "RATE"; 2719 } else if (mask & RES_DONTTRUST) { 2720 sys_restricted++; 2721 code = "DENY"; |
2722 } |
2723 2724 /* 2725 * Here we light up a kiss-of-death packet. Note the 2726 * rate limit on these packets. Once a second initialize 2727 * a bucket counter. Every packet sent decrements the 2728 * counter until reaching zero. If the counter is zero, 2729 * drop the kod. 2730 */ 2731 if (sys_kod == 0 || !(mask & RES_DEMOBILIZE)) 2732 return; 2733 2734 sys_kod--; 2735 memcpy(&xpkt.refid, code, 4); 2736 xpkt.li_vn_mode = PKT_LI_VN_MODE(LEAP_NOTINSYNC, 2737 PKT_VERSION(rpkt->li_vn_mode), xmode); 2738 xpkt.stratum = STRATUM_UNSPEC; |
2739 } else { 2740 xpkt.li_vn_mode = PKT_LI_VN_MODE(sys_leap, 2741 PKT_VERSION(rpkt->li_vn_mode), xmode); 2742 xpkt.stratum = STRATUM_TO_PKT(sys_stratum); 2743 xpkt.refid = sys_refid; 2744 } 2745 xpkt.ppoll = rpkt->ppoll; 2746 xpkt.precision = sys_precision; --- 13 unchanged lines hidden (view full) --- 2760 if (rbufp->recv_length == sendlen) { 2761 get_systime(&xmt_ts); 2762 HTONL_FP(&xmt_ts, &xpkt.xmt); 2763 sendpkt(&rbufp->recv_srcadr, rbufp->dstadr, 0, &xpkt, 2764 sendlen); 2765#ifdef DEBUG 2766 if (debug) 2767 printf("transmit: at %ld %s->%s mode %d\n", |
2768 current_time, stoa(&rbufp->dstadr->sin), 2769 stoa(&rbufp->recv_srcadr), xmode); |
2770#endif 2771 return; 2772 } 2773 2774 /* 2775 * The received packet contains a MAC, so the transmitted packet 2776 * must be authenticated. For private-key cryptography, use the 2777 * predefined private keys to generate the cryptosum. For 2778 * autokey cryptography, use the server private value to 2779 * generate the cookie, which is unique for every source- 2780 * destination-key ID combination. 2781 */ |
2782#ifdef OPENSSL |
2783 if (xkeyid > NTP_MAXKEY) { 2784 keyid_t cookie; |
2785 2786 /* 2787 * The only way to get here is a reply to a legitimate 2788 * client request message, so the mode must be 2789 * MODE_SERVER. If an extension field is present, there 2790 * can be only one and that must be a command. Do what 2791 * needs, but with private value of zero so the poor 2792 * jerk can decode it. If no extension field is present, 2793 * use the cookie to generate the session key. 2794 */ |
2795 cookie = session_key(&rbufp->recv_srcadr, 2796 &rbufp->dstadr->sin, 0, sys_private, 0); |
2797 if (rbufp->recv_length >= (int)(sendlen + MAX_MAC_LEN + 2 * 2798 sizeof(u_int32))) { |
2799 session_key(&rbufp->dstadr->sin, 2800 &rbufp->recv_srcadr, xkeyid, 0, 2); |
2801 temp32 = CRYPTO_RESP; 2802 rpkt->exten[0] |= htonl(temp32); 2803 sendlen += crypto_xmit(&xpkt, 2804 &rbufp->recv_srcadr, sendlen, 2805 (struct exten *)rpkt->exten, cookie); |
2806 } else { 2807 session_key(&rbufp->dstadr->sin, 2808 &rbufp->recv_srcadr, xkeyid, cookie, 2); 2809 } 2810 } |
2811#endif /* OPENSSL */ |
2812 get_systime(&xmt_ts); 2813 L_ADD(&xmt_ts, &sys_authdelay); 2814 HTONL_FP(&xmt_ts, &xpkt.xmt); 2815 authlen = authencrypt(xkeyid, (u_int32 *)&xpkt, sendlen); 2816 sendlen += authlen; |
2817#ifdef OPENSSL |
2818 if (xkeyid > NTP_MAXKEY) 2819 authtrust(xkeyid, 0); |
2820#endif /* OPENSSL */ |
2821 get_systime(&xmt_tx); 2822 if (sendlen > sizeof(xpkt)) { 2823 msyslog(LOG_ERR, "buffer overflow %u", sendlen); |
2824 exit (-1); |
2825 } 2826 sendpkt(&rbufp->recv_srcadr, rbufp->dstadr, 0, &xpkt, sendlen); 2827 2828 /* 2829 * Calculate the encryption delay. Keep the minimum over the 2830 * latest two samples. 2831 */ 2832 L_SUB(&xmt_tx, &xmt_ts); --- 4 unchanged lines hidden (view full) --- 2837 sys_authdelay.l_uf = sys_authdly[0]; 2838 else 2839 sys_authdelay.l_uf = sys_authdly[1]; 2840#ifdef DEBUG 2841 if (debug) 2842 printf( 2843 "transmit: at %ld %s->%s mode %d keyid %08x len %d mac %d\n", 2844 current_time, ntoa(&rbufp->dstadr->sin), |
2845 ntoa(&rbufp->recv_srcadr), xmode, xkeyid, sendlen - 2846 authlen, authlen); |
2847#endif 2848} 2849 2850 |
2851#ifdef OPENSSL |
2852/* 2853 * key_expire - purge the key list 2854 */ 2855void 2856key_expire( 2857 struct peer *peer /* peer structure pointer */ 2858 ) 2859{ 2860 int i; 2861 |
2862 if (peer->keylist != NULL) { |
2863 for (i = 0; i <= peer->keynumber; i++) 2864 authtrust(peer->keylist[i], 0); 2865 free(peer->keylist); 2866 peer->keylist = NULL; 2867 } |
2868 value_free(&peer->sndval); 2869 peer->keynumber = 0; |
2870#ifdef DEBUG 2871 if (debug) 2872 printf("key_expire: at %lu\n", current_time); 2873#endif 2874} |
2875#endif /* OPENSSL */ |
2876 |
2877 |
2878/* |
2879 * Determine if the peer is unfit for synchronization 2880 * 2881 * A peer is unfit for synchronization if 2882 * > not reachable 2883 * > a synchronization loop would form 2884 * > never been synchronized 2885 * > stratum undefined or too high 2886 * > too long without synchronization 2887 * > designated noselect 2888 */ 2889static int /* 0 if no, 1 if yes */ 2890peer_unfit( 2891 struct peer *peer /* peer structure pointer */ 2892 ) 2893{ 2894 return (!peer->reach || (peer->stratum > 1 && peer->refid == 2895 peer->dstadr->addr_refid) || peer->leap == LEAP_NOTINSYNC || 2896 peer->stratum >= STRATUM_UNSPEC || root_distance(peer) >= 2897 MAXDISTANCE + 2. * clock_phi * ULOGTOD(sys_poll) || 2898 peer->flags & FLAG_NOSELECT ); 2899} 2900 2901 2902/* |
2903 * Find the precision of this particular machine 2904 */ |
2905#define MINSTEP 100e-9 /* minimum clock increment (s) */ 2906#define MAXSTEP 20e-3 /* maximum clock increment (s) */ 2907#define MINLOOPS 5 /* minimum number of step samples */ |
2908 2909/* |
2910 * This routine calculates the system precision, defined as the minimum 2911 * of a sequency of differences between successive readings of the 2912 * system clock. However, if the system clock can be read more than once 2913 * during a tick interval, the difference can be zero or one LSB unit, 2914 * where the LSB corresponds to one nanosecond or one microsecond. 2915 * Conceivably, if some other process preempts this one and reads the 2916 * clock, the difference can be more than one LSB unit. 2917 * 2918 * For hardware clock frequencies of 10 MHz or less, we assume the 2919 * logical clock advances only at the hardware clock tick. For higher 2920 * frequencies, we assume the logical clock can advance no more than 100 2921 * nanoseconds between ticks. |
2922 */ 2923int 2924default_get_precision(void) 2925{ |
2926 l_fp val; /* current seconds fraction */ 2927 l_fp last; /* last seconds fraction */ 2928 l_fp diff; /* difference */ 2929 double tick; /* computed tick value */ 2930 double dtemp; /* scratch */ 2931 int i; /* log2 precision */ |
2932 |
2933 /* 2934 * Loop to find tick value in nanoseconds. Toss out outlyer 2935 * values less than the minimun tick value. In wacky cases, use 2936 * the default maximum value. |
2937 */ |
2938 get_systime(&last); 2939 tick = MAXSTEP; 2940 for (i = 0; i < MINLOOPS;) { 2941 get_systime(&val); 2942 diff = val; 2943 L_SUB(&diff, &last); 2944 last = val; 2945 LFPTOD(&diff, dtemp); 2946 if (dtemp < MINSTEP) 2947 continue; 2948 i++; 2949 if (dtemp < tick) 2950 tick = dtemp; |
2951 } |
2952 2953 /* 2954 * Find the nearest power of two. 2955 */ 2956 NLOG(NLOG_SYSEVENT) 2957 msyslog(LOG_INFO, "precision = %.3f usec", tick * 1e6); 2958 for (i = 0; tick <= 1; i++) 2959 tick *= 2; 2960 if (tick - 1. > 1. - tick / 2) 2961 i--; 2962 return (-i); |
2963} 2964 |
2965 |
2966/* |
2967 * kod_proto - called once per second to limit kiss-of-death packets 2968 */ 2969void 2970kod_proto(void) 2971{ 2972 sys_kod = sys_kod_rate; 2973} 2974 2975 2976/* |
2977 * init_proto - initialize the protocol module's data 2978 */ 2979void 2980init_proto(void) 2981{ |
2982 l_fp dummy; 2983 int i; |
2984 2985 /* 2986 * Fill in the sys_* stuff. Default is don't listen to 2987 * broadcasting, authenticate. 2988 */ 2989 sys_leap = LEAP_NOTINSYNC; 2990 sys_stratum = STRATUM_UNSPEC; |
2991 memcpy(&sys_refid, "INIT", 4); |
2992 sys_precision = (s_char)default_get_precision(); 2993 sys_jitter = LOGTOD(sys_precision); 2994 sys_rootdelay = 0; 2995 sys_rootdispersion = 0; |
2996 L_CLR(&sys_reftime); 2997 sys_peer = NULL; 2998 sys_survivors = 0; 2999 get_systime(&dummy); |
3000 sys_manycastserver = 0; |
3001 sys_bclient = 0; 3002 sys_bdelay = DEFBROADDELAY; |
3003 sys_calldelay = BURST_DELAY; |
3004 sys_authenticate = 1; 3005 L_CLR(&sys_authdelay); 3006 sys_authdly[0] = sys_authdly[1] = 0; 3007 sys_stattime = 0; |
3008 proto_clr_stats(); 3009 for (i = 0; i < MAX_TTL; i++) { 3010 sys_ttl[i] = (u_char)((i * 256) / MAX_TTL); 3011 sys_ttlmax = i; 3012 } 3013#ifdef OPENSSL |
3014 sys_automax = 1 << NTP_AUTOMAX; |
3015#endif /* OPENSSL */ |
3016 3017 /* 3018 * Default these to enable 3019 */ 3020 ntp_enable = 1; 3021#ifndef KERNEL_FLL_BUG 3022 kern_enable = 1; 3023#endif 3024 pps_enable = 0; 3025 stats_control = 1; |
3026} 3027 3028 3029/* 3030 * proto_config - configure the protocol module 3031 */ 3032void 3033proto_config( |
3034 int item, 3035 u_long value, 3036 double dvalue, 3037 struct sockaddr_storage* svalue |
3038 ) 3039{ 3040 /* 3041 * Figure out what he wants to change, then do it 3042 */ 3043 switch (item) { |
3044 |
3045 /* 3046 * Turn on/off kernel discipline. 3047 */ 3048 case PROTO_KERNEL: |
3049 kern_enable = (int)value; 3050 break; 3051 |
3052 /* 3053 * Turn on/off clock discipline. 3054 */ |
3055 case PROTO_NTP: |
3056 ntp_enable = (int)value; 3057 break; 3058 |
3059 /* 3060 * Turn on/off monitoring. 3061 */ |
3062 case PROTO_MONITOR: |
3063 if (value) 3064 mon_start(MON_ON); 3065 else 3066 mon_stop(MON_ON); 3067 break; 3068 |
3069 /* 3070 * Turn on/off statistics. 3071 */ |
3072 case PROTO_FILEGEN: |
3073 stats_control = (int)value; 3074 break; 3075 |
3076 /* 3077 * Turn on/off facility to listen to broadcasts. 3078 */ |
3079 case PROTO_BROADCLIENT: |
3080 sys_bclient = (int)value; 3081 if (value) 3082 io_setbclient(); 3083 else 3084 io_unsetbclient(); 3085 break; 3086 |
3087 /* 3088 * Add muliticast group address. 3089 */ |
3090 case PROTO_MULTICAST_ADD: |
3091 if (svalue) 3092 io_multicast_add(*svalue); |
3093 break; 3094 |
3095 /* 3096 * Delete multicast group address. 3097 */ |
3098 case PROTO_MULTICAST_DEL: |
3099 if (svalue) 3100 io_multicast_del(*svalue); |
3101 break; 3102 |
3103 /* 3104 * Set default broadcast delay. 3105 */ |
3106 case PROTO_BROADDELAY: |
3107 sys_bdelay = dvalue; 3108 break; 3109 |
3110 /* 3111 * Set modem call delay. 3112 */ 3113 case PROTO_CALLDELAY: 3114 sys_calldelay = (int)value; 3115 break; |
3116 |
3117 /* 3118 * Require authentication to mobilize ephemeral associations. 3119 */ 3120 case PROTO_AUTHENTICATE: |
3121 sys_authenticate = (int)value; 3122 break; 3123 |
3124 /* 3125 * Turn on/off PPS discipline. 3126 */ |
3127 case PROTO_PPS: |
3128 pps_enable = (int)value; 3129 break; 3130 |
3131 /* 3132 * Set the minimum number of survivors. 3133 */ 3134 case PROTO_MINCLOCK: 3135 sys_minclock = (int)dvalue; 3136 break; 3137 3138 /* 3139 * Set the minimum number of candidates. 3140 */ 3141 case PROTO_MINSANE: 3142 sys_minsane = (int)dvalue; 3143 break; 3144 3145 /* 3146 * Set the stratum floor. 3147 */ 3148 case PROTO_FLOOR: 3149 sys_floor = (int)dvalue; 3150 break; 3151 3152 /* 3153 * Set the stratum ceiling. 3154 */ 3155 case PROTO_CEILING: 3156 sys_ceiling = (int)dvalue; 3157 break; 3158 3159 /* 3160 * Set the cohort switch. 3161 */ 3162 case PROTO_COHORT: 3163 sys_cohort= (int)dvalue; 3164 break; 3165 /* 3166 * Set the adjtime() resolution (s). 3167 */ 3168 case PROTO_ADJ: 3169 sys_tick = dvalue; 3170 break; 3171 |
3172#ifdef REFCLOCK |
3173 /* 3174 * Turn on/off refclock calibrate 3175 */ |
3176 case PROTO_CAL: |
3177 cal_enable = (int)value; 3178 break; 3179#endif |
3180 default: 3181 3182 /* |
3183 * Log this error. |
3184 */ |
3185 msyslog(LOG_INFO, 3186 "proto_config: illegal item %d, value %ld", |
3187 item, value); |
3188 } 3189} 3190 3191 3192/* 3193 * proto_clr_stats - clear protocol stat counters 3194 */ 3195void 3196proto_clr_stats(void) 3197{ |
3198 sys_stattime = current_time; 3199 sys_received = 0; 3200 sys_processed = 0; |
3201 sys_newversionpkt = 0; |
3202 sys_oldversionpkt = 0; |
3203 sys_unknownversion = 0; |
3204 sys_restricted = 0; |
3205 sys_badlength = 0; |
3206 sys_badauth = 0; |
3207 sys_limitrejected = 0; 3208} |