/* * refclock_arc - clock driver for ARCRON MSF/DCF/WWVB receivers */ #ifdef HAVE_CONFIG_H #include <config.h> #endif #if defined(REFCLOCK) && defined(CLOCK_ARCRON_MSF) static const char arc_version[] = { "V1.3 2003/02/21" }; /* define PRE_NTP420 for compatibility to previous versions of NTP (at least to 4.1.0 */ #undef PRE_NTP420 #ifndef ARCRON_NOT_KEEN #define ARCRON_KEEN 1 /* Be keen, and trusting of the clock, if defined. */ #endif #ifndef ARCRON_NOT_MULTIPLE_SAMPLES #define ARCRON_MULTIPLE_SAMPLES 1 /* Use all timestamp bytes as samples. */ #endif #ifndef ARCRON_NOT_LEAPSECOND_KEEN #ifndef ARCRON_LEAPSECOND_KEEN #undef ARCRON_LEAPSECOND_KEEN /* Respond quickly to leap seconds: doesn't work yet. */ #endif #endif /* Code by Derek Mulcahy, <derek@toybox.demon.co.uk>, 1997. Modifications by Damon Hart-Davis, <d@hd.org>, 1997. Modifications by Paul Alfille, <palfille@partners.org>, 2003. Modifications by Christopher Price, <cprice@cs-home.com>, 2003. Modifications by Nigel Roles <nigel@9fs.org>, 2003. THIS CODE IS SUPPLIED AS IS, WITH NO WARRANTY OF ANY KIND. USE AT YOUR OWN RISK. Orginally developed and used with ntp3-5.85 by Derek Mulcahy. Built against ntp3-5.90 on Solaris 2.5 using gcc 2.7.2. This code may be freely copied and used and incorporated in other systems providing the disclaimer and notice of authorship are reproduced. ------------------------------------------------------------------------------- Nigel's notes: 1) Called tcgetattr() before modifying, so that fields correctly initialised for all operating systems 2) Altered parsing of timestamp line so that it copes with fields which are not always ASCII digits (e.g. status field when battery low) ------------------------------------------------------------------------------- Christopher's notes: MAJOR CHANGES SINCE V1.2 ======================== 1) Applied patch by Andrey Bray <abuse@madhouse.demon.co.uk> 2001-02-17 comp.protocols.time.ntp 2) Added WWVB support via clock mode command, localtime/UTC time configured via flag1=(0=UTC, 1=localtime) 3) Added ignore resync request via flag2=(0=resync, 1=ignore resync) 4) Added simplified conversion from localtime to UTC with dst/bst translation 5) Added average signal quality poll 6) Fixed a badformat error when no code is available due to stripping \n & \r's 7) Fixed a badformat error when clearing lencode & memset a_lastcode in poll routine 8) Lots of code cleanup, including standardized DEBUG macros and removal of unused code ------------------------------------------------------------------------------- Author's original note: I enclose my ntp driver for the Galleon Systems Arc MSF receiver. It works (after a fashion) on both Solaris-1 and Solaris-2. I am currently using ntp3-5.85. I have been running the code for about 7 months without any problems. Even coped with the change to BST! I had to do some funky things to read from the clock because it uses the power from the receive lines to drive the transmit lines. This makes the code look a bit stupid but it works. I also had to put in some delays to allow for the turnaround time from receive to transmit. These delays are between characters when requesting a time stamp so that shouldn't affect the results too drastically. ... The bottom line is that it works but could easily be improved. You are free to do what you will with the code. I haven't been able to determine how good the clock is. I think that this requires a known good clock to compare it against. ------------------------------------------------------------------------------- Damon's notes for adjustments: MAJOR CHANGES SINCE V1.0 ======================== 1) Removal of pollcnt variable that made the clock go permanently off-line once two time polls failed to gain responses. 2) Avoiding (at least on Solaris-2) terminal becoming the controlling terminal of the process when we do a low-level open(). 3) Additional logic (conditional on ARCRON_LEAPSECOND_KEEN being defined) to try to resync quickly after a potential leap-second insertion or deletion. 4) Code significantly slimmer at run-time than V1.0. GENERAL ======= 1) The C preprocessor symbol to have the clock built has been changed from ARC to ARCRON_MSF to CLOCK_ARCRON_MSF to minimise the possiblity of clashes with other symbols in the future. 2) PRECISION should be -4/-5 (63ms/31ms) for the following reasons: a) The ARC documentation claims the internal clock is (only) accurate to about 20ms relative to Rugby (plus there must be noticable drift and delay in the ms range due to transmission delays and changing atmospheric effects). This clock is not designed for ms accuracy as NTP has spoilt us all to expect. b) The clock oscillator looks like a simple uncompensated quartz crystal of the sort used in digital watches (ie 32768Hz) which can have large temperature coefficients and drifts; it is not clear if this oscillator is properly disciplined to the MSF transmission, but as the default is to resync only once per *day*, we can imagine that it is not, and is free-running. We can minimise drift by resyncing more often (at the cost of reduced battery life), but drift/wander may still be significant. c) Note that the bit time of 3.3ms adds to the potential error in the the clock timestamp, since the bit clock of the serial link may effectively be free-running with respect to the host clock and the MSF clock. Actually, the error is probably 1/16th of the above, since the input data is probably sampled at at least 16x the bit rate. By keeping the clock marked as not very precise, it will have a fairly large dispersion, and thus will tend to be used as a `backup' time source and sanity checker, which this clock is probably ideal for. For an isolated network without other time sources, this clock can probably be expected to provide *much* better than 1s accuracy, which will be fine. By default, PRECISION is set to -4, but experience, especially at a particular geographic location with a particular clock, may allow this to be altered to -5. (Note that skews of +/- 10ms are to be expected from the clock from time-to-time.) This improvement of reported precision can be instigated by setting flag3 to 1, though the PRECISION will revert to the normal value while the clock signal quality is unknown whatever the flag3 setting. IN ANY CASE, BE SURE TO SET AN APPROPRIATE FUDGE FACTOR TO REMOVE ANY RESIDUAL SKEW, eg: server 127.127.27.0 # ARCRON MSF radio clock unit 0. # Fudge timestamps by about 20ms. fudge 127.127.27.0 time1 0.020 You will need to observe your system's behaviour, assuming you have some other NTP source to compare it with, to work out what the fudge factor should be. For my Sun SS1 running SunOS 4.1.3_U1 with my MSF clock with my distance from the MSF transmitter, +20ms seemed about right, after some observation. 3) REFID has been made "MSFa" to reflect the MSF time source and the ARCRON receiver. 4) DEFAULT_RESYNC_TIME is the time in seconds (by default) before forcing a resync since the last attempt. This is picked to give a little less than an hour between resyncs and to try to avoid clashing with any regular event at a regular time-past-the-hour which might cause systematic errors. The INITIAL_RESYNC_DELAY is to avoid bothering the clock and running down its batteries unnecesarily if ntpd is going to crash or be killed or reconfigured quickly. If ARCRON_KEEN is defined then this period is long enough for (with normal polling rates) enough time samples to have been taken to allow ntpd to sync to the clock before the interruption for the clock to resync to MSF. This avoids ntpd syncing to another peer first and then almost immediately hopping to the MSF clock. The RETRY_RESYNC_TIME is used before rescheduling a resync after a resync failed to reveal a statisfatory signal quality (too low or unknown). 5) The clock seems quite jittery, so I have increased the median-filter size from the typical (previous) value of 3. I discard up to half the results in the filter. It looks like maybe 1 sample in 10 or so (maybe less) is a spike, so allow the median filter to discard at least 10% of its entries or 1 entry, whichever is greater. 6) Sleeping *before* each character sent to the unit to allow required inter-character time but without introducting jitter and delay in handling the response if possible. 7) If the flag ARCRON_KEEN is defined, take time samples whenever possible, even while resyncing, etc. We rely, in this case, on the clock always giving us a reasonable time or else telling us in the status byte at the end of the timestamp that it failed to sync to MSF---thus we should never end up syncing to completely the wrong time. 8) If the flag ARCRON_OWN_FILTER is defined, use own versions of refclock median-filter routines to get round small bug in 3-5.90 code which does not return the median offset. XXX Removed this bit due NTP Version 4 upgrade - dlm. 9) We would appear to have a year-2000 problem with this clock since it returns only the two least-significant digits of the year. But ntpd ignores the year and uses the local-system year instead, so this is in fact not a problem. Nevertheless, we attempt to do a sensible thing with the dates, wrapping them into a 100-year window. 10)Logs stats information that can be used by Derek's Tcl/Tk utility to show the status of the clock. 11)The clock documentation insists that the number of bits per character to be sent to the clock, and sent by it, is 11, including one start bit and two stop bits. The data format is either 7+even or 8+none. TO-DO LIST ========== * Eliminate use of scanf(), and maybe sprintf(). * Allow user setting of resync interval to trade battery life for accuracy; maybe could be done via fudge factor or unit number. * Possibly note the time since the last resync of the MSF clock to MSF as the age of the last reference timestamp, ie trust the clock's oscillator not very much... * Add very slow auto-adjustment up to a value of +/- time2 to correct for long-term errors in the clock value (time2 defaults to 0 so the correction would be disabled by default). * Consider trying to use the tty_clk/ppsclock support. * Possibly use average or maximum signal quality reported during resync, rather than just the last one, which may be atypical. */ /* Notes for HKW Elektronik GmBH Radio clock driver */ /* Author Lyndon David, Sentinet Ltd, Feb 1997 */ /* These notes seem also to apply usefully to the ARCRON clock. */ /* The HKW clock module is a radio receiver tuned into the Rugby */ /* MSF time signal tranmitted on 60 kHz. The clock module connects */ /* to the computer via a serial line and transmits the time encoded */ /* in 15 bytes at 300 baud 7 bits two stop bits even parity */ /* Clock communications, from the datasheet */ /* All characters sent to the clock are echoed back to the controlling */ /* device. */ /* Transmit time/date information */ /* syntax ASCII o<cr> */ /* Character o may be replaced if neccesary by a character whose code */ /* contains the lowest four bits f(hex) eg */ /* syntax binary: xxxx1111 00001101 */ /* DHD note: You have to wait for character echo + 10ms before sending next character. */ /* The clock replies to this command with a sequence of 15 characters */ /* which contain the complete time and a final <cr> making 16 characters */ /* in total. */ /* The RC computer clock will not reply immediately to this command because */ /* the start bit edge of the first reply character marks the beginning of */ /* the second. So the RC Computer Clock will reply to this command at the */ /* start of the next second */ /* The characters have the following meaning */ /* 1. hours tens */ /* 2. hours units */ /* 3. minutes tens */ /* 4. minutes units */ /* 5. seconds tens */ /* 6. seconds units */ /* 7. day of week 1-monday 7-sunday */ /* 8. day of month tens */ /* 9. day of month units */ /* 10. month tens */ /* 11. month units */ /* 12. year tens */ /* 13. year units */ /* 14. BST/UTC status */ /* bit 7 parity */ /* bit 6 always 0 */ /* bit 5 always 1 */ /* bit 4 always 1 */ /* bit 3 always 0 */ /* bit 2 =1 if UTC is in effect, complementary to the BST bit */ /* bit 1 =1 if BST is in effect, according to the BST bit */ /* bit 0 BST/UTC change impending bit=1 in case of change impending */ /* 15. status */ /* bit 7 parity */ /* bit 6 always 0 */ /* bit 5 always 1 */ /* bit 4 always 1 */ /* bit 3 =1 if low battery is detected */ /* bit 2 =1 if the very last reception attempt failed and a valid */ /* time information already exists (bit0=1) */ /* =0 if the last reception attempt was successful */ /* bit 1 =1 if at least one reception since 2:30 am was successful */ /* =0 if no reception attempt since 2:30 am was successful */ /* bit 0 =1 if the RC Computer Clock contains valid time information */ /* This bit is zero after reset and one after the first */ /* successful reception attempt */ /* DHD note: Also note g<cr> command which confirms that a resync is in progress, and if so what signal quality (0--5) is available. Also note h<cr> command which starts a resync to MSF signal. */ #include "ntpd.h" #include "ntp_io.h" #include "ntp_refclock.h" #include "ntp_calendar.h" #include "ntp_stdlib.h" #include <stdio.h> #include <ctype.h> #if defined(HAVE_BSD_TTYS) #include <sgtty.h> #endif /* HAVE_BSD_TTYS */ #if defined(HAVE_SYSV_TTYS) #include <termio.h> #endif /* HAVE_SYSV_TTYS */ #if defined(HAVE_TERMIOS) #include <termios.h> #endif /* * This driver supports the ARCRON MSF/DCF/WWVB Radio Controlled Clock */ /* * Interface definitions */ #define DEVICE "/dev/arc%d" /* Device name and unit. */ #define SPEED B300 /* UART speed (300 baud) */ #define PRECISION (-4) /* Precision (~63 ms). */ #define HIGHPRECISION (-5) /* If things are going well... */ #define REFID "MSFa" /* Reference ID. */ #define REFID_MSF "MSF" /* Reference ID. */ #define REFID_DCF77 "DCF" /* Reference ID. */ #define REFID_WWVB "WWVB" /* Reference ID. */ #define DESCRIPTION "ARCRON MSF/DCF/WWVB Receiver" #ifdef PRE_NTP420 #define MODE ttlmax #else #define MODE ttl #endif #define LENARC 16 /* Format `o' timecode length. */ #define BITSPERCHAR 11 /* Bits per character. */ #define BITTIME 0x0DA740E /* Time for 1 bit at 300bps. */ #define CHARTIME10 0x8888888 /* Time for 10-bit char at 300bps. */ #define CHARTIME11 0x962FC96 /* Time for 11-bit char at 300bps. */ #define CHARTIME /* Time for char at 300bps. */ \ ( (BITSPERCHAR == 11) ? CHARTIME11 : ( (BITSPERCHAR == 10) ? CHARTIME10 : \ (BITSPERCHAR * BITTIME) ) ) /* Allow for UART to accept char half-way through final stop bit. */ #define INITIALOFFSET (u_int32)(-BITTIME/2) /* charoffsets[x] is the time after the start of the second that byte x (with the first byte being byte 1) is received by the UART, assuming that the initial edge of the start bit of the first byte is on-time. The values are represented as the fractional part of an l_fp. We store enough values to have the offset of each byte including the trailing \r, on the assumption that the bytes follow one another without gaps. */ static const u_int32 charoffsets[LENARC+1] = { #if BITSPERCHAR == 11 /* Usual case. */ /* Offsets computed as accurately as possible... */ 0, INITIALOFFSET + 0x0962fc96, /* 1 chars, 11 bits */ INITIALOFFSET + 0x12c5f92c, /* 2 chars, 22 bits */ INITIALOFFSET + 0x1c28f5c3, /* 3 chars, 33 bits */ INITIALOFFSET + 0x258bf259, /* 4 chars, 44 bits */ INITIALOFFSET + 0x2eeeeeef, /* 5 chars, 55 bits */ INITIALOFFSET + 0x3851eb85, /* 6 chars, 66 bits */ INITIALOFFSET + 0x41b4e81b, /* 7 chars, 77 bits */ INITIALOFFSET + 0x4b17e4b1, /* 8 chars, 88 bits */ INITIALOFFSET + 0x547ae148, /* 9 chars, 99 bits */ INITIALOFFSET + 0x5dddddde, /* 10 chars, 110 bits */ INITIALOFFSET + 0x6740da74, /* 11 chars, 121 bits */ INITIALOFFSET + 0x70a3d70a, /* 12 chars, 132 bits */ INITIALOFFSET + 0x7a06d3a0, /* 13 chars, 143 bits */ INITIALOFFSET + 0x8369d037, /* 14 chars, 154 bits */ INITIALOFFSET + 0x8ccccccd, /* 15 chars, 165 bits */ INITIALOFFSET + 0x962fc963 /* 16 chars, 176 bits */ #else /* Offsets computed with a small rounding error... */ 0, INITIALOFFSET + 1 * CHARTIME, INITIALOFFSET + 2 * CHARTIME, INITIALOFFSET + 3 * CHARTIME, INITIALOFFSET + 4 * CHARTIME, INITIALOFFSET + 5 * CHARTIME, INITIALOFFSET + 6 * CHARTIME, INITIALOFFSET + 7 * CHARTIME, INITIALOFFSET + 8 * CHARTIME, INITIALOFFSET + 9 * CHARTIME, INITIALOFFSET + 10 * CHARTIME, INITIALOFFSET + 11 * CHARTIME, INITIALOFFSET + 12 * CHARTIME, INITIALOFFSET + 13 * CHARTIME, INITIALOFFSET + 14 * CHARTIME, INITIALOFFSET + 15 * CHARTIME, INITIALOFFSET + 16 * CHARTIME #endif }; #define DEFAULT_RESYNC_TIME (57*60) /* Gap between resync attempts (s). */ #define RETRY_RESYNC_TIME (27*60) /* Gap to emergency resync attempt. */ #ifdef ARCRON_KEEN #define INITIAL_RESYNC_DELAY 500 /* Delay before first resync. */ #else #define INITIAL_RESYNC_DELAY 50 /* Delay before first resync. */ #endif static const int moff[12] = { 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334 }; /* Flags for a raw open() of the clock serial device. */ #ifdef O_NOCTTY /* Good, we can avoid tty becoming controlling tty. */ #define OPEN_FLAGS (O_RDWR | O_NOCTTY) #else /* Oh well, it may not matter... */ #define OPEN_FLAGS (O_RDWR) #endif /* Length of queue of command bytes to be sent. */ #define CMDQUEUELEN 4 /* Enough for two cmds + each \r. */ /* Queue tick time; interval in seconds between chars taken off queue. */ /* Must be >= 2 to allow o\r response to come back uninterrupted. */ #define QUEUETICK 2 /* Allow o\r reply to finish. */ /* * ARC unit control structure */ struct arcunit { l_fp lastrec; /* Time tag for the receive time (system). */ int status; /* Clock status. */ int quality; /* Quality of reception 0--5 for unit. */ /* We may also use the values -1 or 6 internally. */ u_long quality_stamp; /* Next time to reset quality average. */ u_long next_resync; /* Next resync time (s) compared to current_time. */ int resyncing; /* Resync in progress if true. */ /* In the outgoing queue, cmdqueue[0] is next to be sent. */ char cmdqueue[CMDQUEUELEN+1]; /* Queue of outgoing commands + \0. */ u_long saved_flags; /* Saved fudge flags. */ }; #ifdef ARCRON_LEAPSECOND_KEEN /* The flag `possible_leap' is set non-zero when any MSF unit thinks a leap-second may have happened. Set whenever we receive a valid time sample in the first hour of the first day of the first/seventh months. Outside the special hour this value is unconditionally set to zero by the receive routine. On finding itself in this timeslot, as long as the value is non-negative, the receive routine sets it to a positive value to indicate a resync to MSF should be performed. In the poll routine, if this value is positive and we are not already resyncing (eg from a sync that started just before midnight), start resyncing and set this value negative to indicate that a leap-triggered resync has been started. Having set this negative prevents the receive routine setting it positive and thus prevents multiple resyncs during the witching hour. */ static int possible_leap = 0; /* No resync required by default. */ #endif #if 0 static void dummy_event_handler (struct peer *); static void arc_event_handler (struct peer *); #endif /* 0 */ #define QUALITY_UNKNOWN -1 /* Indicates unknown clock quality. */ #define MIN_CLOCK_QUALITY 0 /* Min quality clock will return. */ #define MIN_CLOCK_QUALITY_OK 3 /* Min quality for OK reception. */ #define MAX_CLOCK_QUALITY 5 /* Max quality clock will return. */ /* * Function prototypes */ static int arc_start (int, struct peer *); static void arc_shutdown (int, struct peer *); static void arc_receive (struct recvbuf *); static void arc_poll (int, struct peer *); /* * Transfer vector */ struct refclock refclock_arc = { arc_start, /* start up driver */ arc_shutdown, /* shut down driver */ arc_poll, /* transmit poll message */ noentry, /* not used (old arc_control) */ noentry, /* initialize driver (not used) */ noentry, /* not used (old arc_buginfo) */ NOFLAGS /* not used */ }; /* Queue us up for the next tick. */ #define ENQUEUE(up) \ do { \ peer->nextaction = current_time + QUEUETICK; \ } while(0) /* Placeholder event handler---does nothing safely---soaks up loose tick. */ static void dummy_event_handler( struct peer *peer ) { #ifdef DEBUG if(debug) { printf("arc: dummy_event_handler() called.\n"); } #endif } /* Normal event handler. Take first character off queue and send to clock if not a null. Shift characters down and put a null on the end. We assume that there is no parallelism so no race condition, but even if there is nothing bad will happen except that we might send some bad data to the clock once in a while. */ static void arc_event_handler( struct peer *peer ) { struct refclockproc *pp = peer->procptr; register struct arcunit *up = (struct arcunit *)pp->unitptr; int i; char c; #ifdef DEBUG if(debug > 2) { printf("arc: arc_event_handler() called.\n"); } #endif c = up->cmdqueue[0]; /* Next char to be sent. */ /* Shift down characters, shifting trailing \0 in at end. */ for(i = 0; i < CMDQUEUELEN; ++i) { up->cmdqueue[i] = up->cmdqueue[i+1]; } /* Don't send '\0' characters. */ if(c != '\0') { if(write(pp->io.fd, &c, 1) != 1) { msyslog(LOG_NOTICE, "ARCRON: write to fd %d failed", pp->io.fd); } #ifdef DEBUG else if(debug) { printf("arc: sent `%2.2x', fd %d.\n", c, pp->io.fd); } #endif } ENQUEUE(up); } /* * arc_start - open the devices and initialize data for processing */ static int arc_start( int unit, struct peer *peer ) { register struct arcunit *up; struct refclockproc *pp; int fd; char device[20]; #ifdef HAVE_TERMIOS struct termios arg; #endif msyslog(LOG_NOTICE, "ARCRON: %s: opening unit %d", arc_version, unit); #ifdef DEBUG if(debug) { printf("arc: %s: attempt to open unit %d.\n", arc_version, unit); } #endif /* Prevent a ridiculous device number causing overflow of device[]. */ if((unit < 0) || (unit > 255)) { return(0); } /* * Open serial port. Use CLK line discipline, if available. */ (void)sprintf(device, DEVICE, unit); if (!(fd = refclock_open(device, SPEED, LDISC_CLK))) return(0); #ifdef DEBUG if(debug) { printf("arc: unit %d using open().\n", unit); } #endif fd = tty_open(device, OPEN_FLAGS, 0777); if(fd < 0) { #ifdef DEBUG if(debug) { printf("arc: failed [tty_open()] to open %s.\n", device); } #endif return(0); } #ifndef SYS_WINNT fcntl(fd, F_SETFL, 0); /* clear the descriptor flags */ #endif #ifdef DEBUG if(debug) { printf("arc: opened RS232 port with file descriptor %d.\n", fd); } #endif #ifdef HAVE_TERMIOS tcgetattr(fd, &arg); arg.c_iflag = IGNBRK | ISTRIP; arg.c_oflag = 0; arg.c_cflag = B300 | CS8 | CREAD | CLOCAL | CSTOPB; arg.c_lflag = 0; arg.c_cc[VMIN] = 1; arg.c_cc[VTIME] = 0; tcsetattr(fd, TCSANOW, &arg); #else msyslog(LOG_ERR, "ARCRON: termios not supported in this driver"); (void)close(fd); return 0; #endif up = (struct arcunit *) emalloc(sizeof(struct arcunit)); if(!up) { (void) close(fd); return(0); } /* Set structure to all zeros... */ memset((char *)up, 0, sizeof(struct arcunit)); pp = peer->procptr; pp->io.clock_recv = arc_receive; pp->io.srcclock = (caddr_t)peer; pp->io.datalen = 0; pp->io.fd = fd; if(!io_addclock(&pp->io)) { (void) close(fd); free(up); return(0); } pp->unitptr = (caddr_t)up; /* * Initialize miscellaneous variables */ peer->precision = PRECISION; peer->stratum = 2; /* Default to stratum 2 not 0. */ pp->clockdesc = DESCRIPTION; if (peer->MODE > 3) { msyslog(LOG_NOTICE, "ARCRON: Invalid mode %d", peer->MODE); return 0; } #ifdef DEBUG if(debug) { printf("arc: mode = %d.\n", peer->MODE); } #endif switch (peer->MODE) { case 1: memcpy((char *)&pp->refid, REFID_MSF, 4); break; case 2: memcpy((char *)&pp->refid, REFID_DCF77, 4); break; case 3: memcpy((char *)&pp->refid, REFID_WWVB, 4); break; default: memcpy((char *)&pp->refid, REFID, 4); break; } /* Spread out resyncs so that they should remain separated. */ up->next_resync = current_time + INITIAL_RESYNC_DELAY + (67*unit)%1009; #if 0 /* Not needed because of zeroing of arcunit structure... */ up->resyncing = 0; /* Not resyncing yet. */ up->saved_flags = 0; /* Default is all flags off. */ /* Clear send buffer out... */ { int i; for(i = CMDQUEUELEN; i >= 0; --i) { up->cmdqueue[i] = '\0'; } } #endif #ifdef ARCRON_KEEN up->quality = QUALITY_UNKNOWN; /* Trust the clock immediately. */ #else up->quality = MIN_CLOCK_QUALITY;/* Don't trust the clock yet. */ #endif peer->action = arc_event_handler; ENQUEUE(up); return(1); } /* * arc_shutdown - shut down the clock */ static void arc_shutdown( int unit, struct peer *peer ) { register struct arcunit *up; struct refclockproc *pp; peer->action = dummy_event_handler; pp = peer->procptr; up = (struct arcunit *)pp->unitptr; io_closeclock(&pp->io); free(up); } /* Compute space left in output buffer. */ static int space_left( register struct arcunit *up ) { int spaceleft; /* Compute space left in buffer after any pending output. */ for(spaceleft = 0; spaceleft < CMDQUEUELEN; ++spaceleft) { if(up->cmdqueue[CMDQUEUELEN - 1 - spaceleft] != '\0') { break; } } return(spaceleft); } /* Send command by copying into command buffer as far forward as possible, after any pending output. Indicate an error by returning 0 if there is not space for the command. */ static int send_slow( register struct arcunit *up, int fd, const char *s ) { int sl = strlen(s); int spaceleft = space_left(up); #ifdef DEBUG if(debug > 1) { printf("arc: spaceleft = %d.\n", spaceleft); } #endif if(spaceleft < sl) { /* Should not normally happen... */ #ifdef DEBUG msyslog(LOG_NOTICE, "ARCRON: send-buffer overrun (%d/%d)", sl, spaceleft); #endif return(0); /* FAILED! */ } /* Copy in the command to be sent. */ while(*s && spaceleft > 0) { up->cmdqueue[CMDQUEUELEN - spaceleft--] = *s++; } return(1); } static int get2(char *p, int *val) { if (!isdigit((int)p[0]) || !isdigit((int)p[1])) return 0; *val = (p[0] - '0') * 10 + p[1] - '0'; return 1; } static int get1(char *p, int *val) { if (!isdigit((int)p[0])) return 0; *val = p[0] - '0'; return 1; } /* Macro indicating action we will take for different quality values. */ #define quality_action(q) \ (((q) == QUALITY_UNKNOWN) ? "UNKNOWN, will use clock anyway" : \ (((q) < MIN_CLOCK_QUALITY_OK) ? "TOO POOR, will not use clock" : \ "OK, will use clock")) /* * arc_receive - receive data from the serial interface */ static void arc_receive( struct recvbuf *rbufp ) { register struct arcunit *up; struct refclockproc *pp; struct peer *peer; char c; int i, n, wday, month, flags, status; int arc_last_offset; static int quality_average = 0; static int quality_sum = 0; static int quality_polls = 0; /* * Initialize pointers and read the timecode and timestamp */ peer = (struct peer *)rbufp->recv_srcclock; pp = peer->procptr; up = (struct arcunit *)pp->unitptr; /* If the command buffer is empty, and we are resyncing, insert a g\r quality request into it to poll for signal quality again. */ if((up->resyncing) && (space_left(up) == CMDQUEUELEN)) { #ifdef DEBUG if(debug > 1) { printf("arc: inserting signal-quality poll.\n"); } #endif send_slow(up, pp->io.fd, "g\r"); } /* The `arc_last_offset' is the offset in lastcode[] of the last byte received, and which we assume actually received the input timestamp. (When we get round to using tty_clk and it is available, we assume that we will receive the whole timecode with the trailing \r, and that that \r will be timestamped. But this assumption also works if receive the characters one-by-one.) */ arc_last_offset = pp->lencode+rbufp->recv_length - 1; /* We catch a timestamp iff: * The command code is `o' for a timestamp. * If ARCRON_MULTIPLE_SAMPLES is undefined then we must have exactly char in the buffer (the command code) so that we only sample the first character of the timecode as our `on-time' character. * The first character in the buffer is not the echoed `\r' from the `o` command (so if we are to timestamp an `\r' it must not be first in the receive buffer with lencode==1. (Even if we had other characters following it, we probably would have a premature timestamp on the '\r'.) * We have received at least one character (I cannot imagine how it could be otherwise, but anyway...). */ c = rbufp->recv_buffer[0]; if((pp->a_lastcode[0] == 'o') && #ifndef ARCRON_MULTIPLE_SAMPLES (pp->lencode == 1) && #endif ((pp->lencode != 1) || (c != '\r')) && (arc_last_offset >= 1)) { /* Note that the timestamp should be corrected if >1 char rcvd. */ l_fp timestamp; timestamp = rbufp->recv_time; #ifdef DEBUG if(debug) { /* Show \r as `R', other non-printing char as `?'. */ printf("arc: stamp -->%c<-- (%d chars rcvd)\n", ((c == '\r') ? 'R' : (isgraph((int)c) ? c : '?')), rbufp->recv_length); } #endif /* Now correct timestamp by offset of last byte received---we subtract from the receive time the delay implied by the extra characters received. Reject the input if the resulting code is too long, but allow for the trailing \r, normally not used but a good handle for tty_clk or somesuch kernel timestamper. */ if(arc_last_offset > LENARC) { #ifdef DEBUG if(debug) { printf("arc: input code too long (%d cf %d); rejected.\n", arc_last_offset, LENARC); } #endif pp->lencode = 0; refclock_report(peer, CEVNT_BADREPLY); return; } L_SUBUF(×tamp, charoffsets[arc_last_offset]); #ifdef DEBUG if(debug > 1) { printf( "arc: %s%d char(s) rcvd, the last for lastcode[%d]; -%sms offset applied.\n", ((rbufp->recv_length > 1) ? "*** " : ""), rbufp->recv_length, arc_last_offset, mfptoms((unsigned long)0, charoffsets[arc_last_offset], 1)); } #endif #ifdef ARCRON_MULTIPLE_SAMPLES /* If taking multiple samples, capture the current adjusted sample iff: * No timestamp has yet been captured (it is zero), OR * This adjusted timestamp is earlier than the one already captured, on the grounds that this one suffered less delay in being delivered to us and is more accurate. */ if(L_ISZERO(&(up->lastrec)) || L_ISGEQ(&(up->lastrec), ×tamp)) #endif { #ifdef DEBUG if(debug > 1) { printf("arc: system timestamp captured.\n"); #ifdef ARCRON_MULTIPLE_SAMPLES if(!L_ISZERO(&(up->lastrec))) { l_fp diff; diff = up->lastrec; L_SUB(&diff, ×tamp); printf("arc: adjusted timestamp by -%sms.\n", mfptoms(diff.l_i, diff.l_f, 3)); } #endif } #endif up->lastrec = timestamp; } } /* Just in case we still have lots of rubbish in the buffer... */ /* ...and to avoid the same timestamp being reused by mistake, */ /* eg on receipt of the \r coming in on its own after the */ /* timecode. */ if(pp->lencode >= LENARC) { #ifdef DEBUG if(debug && (rbufp->recv_buffer[0] != '\r')) { printf("arc: rubbish in pp->a_lastcode[].\n"); } #endif pp->lencode = 0; return; } /* Append input to code buffer, avoiding overflow. */ for(i = 0; i < rbufp->recv_length; i++) { if(pp->lencode >= LENARC) { break; } /* Avoid overflow... */ c = rbufp->recv_buffer[i]; /* Drop trailing '\r's and drop `h' command echo totally. */ if(c != '\r' && c != 'h') { pp->a_lastcode[pp->lencode++] = c; } /* If we've just put an `o' in the lastcode[0], clear the timestamp in anticipation of a timecode arriving soon. We would expect to get to process this before any of the timecode arrives. */ if((c == 'o') && (pp->lencode == 1)) { L_CLR(&(up->lastrec)); #ifdef DEBUG if(debug > 1) { printf("arc: clearing timestamp.\n"); } #endif } } if (pp->lencode == 0) return; /* Handle a quality message. */ if(pp->a_lastcode[0] == 'g') { int r, q; if(pp->lencode < 3) { return; } /* Need more data... */ r = (pp->a_lastcode[1] & 0x7f); /* Strip parity. */ q = (pp->a_lastcode[2] & 0x7f); /* Strip parity. */ if(((q & 0x70) != 0x30) || ((q & 0xf) > MAX_CLOCK_QUALITY) || ((r & 0x70) != 0x30)) { /* Badly formatted response. */ #ifdef DEBUG if(debug) { printf("arc: bad `g' response %2x %2x.\n", r, q); } #endif return; } if(r == '3') { /* Only use quality value whilst sync in progress. */ if (up->quality_stamp < current_time) { struct calendar cal; l_fp new_stamp; get_systime (&new_stamp); caljulian (new_stamp.l_ui, &cal); up->quality_stamp = current_time + 60 - cal.second + 5; quality_sum = 0; quality_polls = 0; } quality_sum += (q & 0xf); quality_polls++; quality_average = (quality_sum / quality_polls); #ifdef DEBUG if(debug) { printf("arc: signal quality %d (%d).\n", quality_average, (q & 0xf)); } #endif } else if( /* (r == '2') && */ up->resyncing) { up->quality = quality_average; #ifdef DEBUG if(debug) { printf("arc: sync finished, signal quality %d: %s\n", up->quality, quality_action(up->quality)); } #endif msyslog(LOG_NOTICE, "ARCRON: sync finished, signal quality %d: %s", up->quality, quality_action(up->quality)); up->resyncing = 0; /* Resync is over. */ quality_average = 0; quality_sum = 0; quality_polls = 0; #ifdef ARCRON_KEEN /* Clock quality dubious; resync earlier than usual. */ if((up->quality == QUALITY_UNKNOWN) || (up->quality < MIN_CLOCK_QUALITY_OK)) { up->next_resync = current_time + RETRY_RESYNC_TIME; } #endif } pp->lencode = 0; return; } /* Stop now if this is not a timecode message. */ if(pp->a_lastcode[0] != 'o') { pp->lencode = 0; refclock_report(peer, CEVNT_BADREPLY); return; } /* If we don't have enough data, wait for more... */ if(pp->lencode < LENARC) { return; } /* WE HAVE NOW COLLECTED ONE TIMESTAMP (phew)... */ #ifdef DEBUG if(debug > 1) { printf("arc: NOW HAVE TIMESTAMP...\n"); } #endif /* But check that we actually captured a system timestamp on it. */ if(L_ISZERO(&(up->lastrec))) { #ifdef DEBUG if(debug) { printf("arc: FAILED TO GET SYSTEM TIMESTAMP\n"); } #endif pp->lencode = 0; refclock_report(peer, CEVNT_BADREPLY); return; } /* Append a mark of the clock's received signal quality for the benefit of Derek Mulcahy's Tcl/Tk utility (we map the `unknown' quality value to `6' for his s/w) and terminate the string for sure. This should not go off the buffer end. */ pp->a_lastcode[pp->lencode] = ((up->quality == QUALITY_UNKNOWN) ? '6' : ('0' + up->quality)); pp->a_lastcode[pp->lencode + 1] = '\0'; /* Terminate for printf(). */ #ifdef PRE_NTP420 /* We don't use the micro-/milli- second part... */ pp->usec = 0; pp->msec = 0; #else /* We don't use the nano-second part... */ pp->nsec = 0; #endif /* Validate format and numbers. */ if (pp->a_lastcode[0] != 'o' || !get2(pp->a_lastcode + 1, &pp->hour) || !get2(pp->a_lastcode + 3, &pp->minute) || !get2(pp->a_lastcode + 5, &pp->second) || !get1(pp->a_lastcode + 7, &wday) || !get2(pp->a_lastcode + 8, &pp->day) || !get2(pp->a_lastcode + 10, &month) || !get2(pp->a_lastcode + 12, &pp->year)) { #ifdef DEBUG /* Would expect to have caught major problems already... */ if(debug) { printf("arc: badly formatted data.\n"); } #endif pp->lencode = 0; refclock_report(peer, CEVNT_BADREPLY); return; } flags = pp->a_lastcode[14]; status = pp->a_lastcode[15]; #ifdef DEBUG if(debug) { printf("arc: status 0x%.2x flags 0x%.2x\n", flags, status); } #endif n = 9; /* Validate received values at least enough to prevent internal array-bounds problems, etc. */ if((pp->hour < 0) || (pp->hour > 23) || (pp->minute < 0) || (pp->minute > 59) || (pp->second < 0) || (pp->second > 60) /*Allow for leap seconds.*/ || (wday < 1) || (wday > 7) || (pp->day < 1) || (pp->day > 31) || (month < 1) || (month > 12) || (pp->year < 0) || (pp->year > 99)) { /* Data out of range. */ pp->lencode = 0; refclock_report(peer, CEVNT_BADREPLY); return; } if(peer->MODE == 0) { /* compatiblity to original version */ int bst = flags; /* Check that BST/UTC bits are the complement of one another. */ if(!(bst & 2) == !(bst & 4)) { pp->lencode = 0; refclock_report(peer, CEVNT_BADREPLY); return; } } if(status & 0x8) { msyslog(LOG_NOTICE, "ARCRON: battery low"); } /* Year-2000 alert! */ /* Attempt to wrap 2-digit date into sensible window. */ if(pp->year < YEAR_PIVOT) { pp->year += 100; } /* Y2KFixes */ pp->year += 1900; /* use full four-digit year */ /* Y2KFixes */ /* Attempt to do the right thing by screaming that the code will soon break when we get to the end of its useful life. What a hero I am... PLEASE FIX LEAP-YEAR AND WRAP CODE IN 209X! */ if(pp->year >= YEAR_PIVOT+2000-2 ) { /* Y2KFixes */ /*This should get attention B^> */ msyslog(LOG_NOTICE, "ARCRON: fix me! EITHER YOUR DATE IS BADLY WRONG or else I will break soon!"); } #ifdef DEBUG if(debug) { printf("arc: n=%d %02d:%02d:%02d %02d/%02d/%04d %1d %1d\n", n, pp->hour, pp->minute, pp->second, pp->day, month, pp->year, flags, status); } #endif /* The status value tested for is not strictly supported by the clock spec since the value of bit 2 (0x4) is claimed to be undefined for MSF, yet does seem to indicate if the last resync was successful or not. */ pp->leap = LEAP_NOWARNING; status &= 0x7; if(status == 0x3) { if(status != up->status) { msyslog(LOG_NOTICE, "ARCRON: signal acquired"); } } else { if(status != up->status) { msyslog(LOG_NOTICE, "ARCRON: signal lost"); pp->leap = LEAP_NOTINSYNC; /* MSF clock is free-running. */ up->status = status; pp->lencode = 0; refclock_report(peer, CEVNT_FAULT); return; } } up->status = status; if (peer->MODE == 0) { /* compatiblity to original version */ int bst = flags; pp->day += moff[month - 1]; if(isleap_4(pp->year) && month > 2) { pp->day++; }/* Y2KFixes */ /* Convert to UTC if required */ if(bst & 2) { pp->hour--; if (pp->hour < 0) { pp->hour = 23; pp->day--; /* If we try to wrap round the year * (BST on 1st Jan), reject.*/ if(pp->day < 0) { pp->lencode = 0; refclock_report(peer, CEVNT_BADTIME); return; } } } } if(peer->MODE > 0) { if(pp->sloppyclockflag & CLK_FLAG1) { struct tm local; struct tm *gmtp; time_t unixtime; /* * Convert to GMT for sites that distribute localtime. * This means we have to do Y2K conversion on the * 2-digit year; otherwise, we get the time wrong. */ memset(&local, 0, sizeof(local)); local.tm_year = pp->year-1900; local.tm_mon = month-1; local.tm_mday = pp->day; local.tm_hour = pp->hour; local.tm_min = pp->minute; local.tm_sec = pp->second; switch (peer->MODE) { case 1: local.tm_isdst = (flags & 2); break; case 2: local.tm_isdst = (flags & 2); break; case 3: switch (flags & 3) { case 0: /* It is unclear exactly when the Arcron changes from DST->ST and ST->DST. Testing has shown this to be irregular. For the time being, let the OS decide. */ local.tm_isdst = 0; #ifdef DEBUG if (debug) printf ("arc: DST = 00 (0)\n"); #endif break; case 1: /* dst->st time */ local.tm_isdst = -1; #ifdef DEBUG if (debug) printf ("arc: DST = 01 (1)\n"); #endif break; case 2: /* st->dst time */ local.tm_isdst = -1; #ifdef DEBUG if (debug) printf ("arc: DST = 10 (2)\n"); #endif break; case 3: /* dst time */ local.tm_isdst = 1; #ifdef DEBUG if (debug) printf ("arc: DST = 11 (3)\n"); #endif break; } break; default: msyslog(LOG_NOTICE, "ARCRON: Invalid mode %d", peer->MODE); return; break; } unixtime = mktime (&local); if ((gmtp = gmtime (&unixtime)) == NULL) { pp->lencode = 0; refclock_report (peer, CEVNT_FAULT); return; } pp->year = gmtp->tm_year+1900; month = gmtp->tm_mon+1; pp->day = ymd2yd(pp->year,month,gmtp->tm_mday); /* pp->day = gmtp->tm_yday; */ pp->hour = gmtp->tm_hour; pp->minute = gmtp->tm_min; pp->second = gmtp->tm_sec; #ifdef DEBUG if (debug) { printf ("arc: time is %04d/%02d/%02d %02d:%02d:%02d UTC\n", pp->year,month,gmtp->tm_mday,pp->hour,pp->minute, pp->second); } #endif } else { /* * For more rational sites distributing UTC */ pp->day = ymd2yd(pp->year,month,pp->day); } } if (peer->MODE == 0) { /* compatiblity to original version */ /* If clock signal quality is * unknown, revert to default PRECISION...*/ if(up->quality == QUALITY_UNKNOWN) { peer->precision = PRECISION; } else { /* ...else improve precision if flag3 is set... */ peer->precision = ((pp->sloppyclockflag & CLK_FLAG3) ? HIGHPRECISION : PRECISION); } } else { if ((status == 0x3) && (pp->sloppyclockflag & CLK_FLAG2)) { peer->precision = ((pp->sloppyclockflag & CLK_FLAG3) ? HIGHPRECISION : PRECISION); } else if (up->quality == QUALITY_UNKNOWN) { peer->precision = PRECISION; } else { peer->precision = ((pp->sloppyclockflag & CLK_FLAG3) ? HIGHPRECISION : PRECISION); } } /* Notice and log any change (eg from initial defaults) for flags. */ if(up->saved_flags != pp->sloppyclockflag) { #ifdef DEBUG msyslog(LOG_NOTICE, "ARCRON: flags enabled: %s%s%s%s", ((pp->sloppyclockflag & CLK_FLAG1) ? "1" : "."), ((pp->sloppyclockflag & CLK_FLAG2) ? "2" : "."), ((pp->sloppyclockflag & CLK_FLAG3) ? "3" : "."), ((pp->sloppyclockflag & CLK_FLAG4) ? "4" : ".")); /* Note effects of flags changing... */ if(debug) { printf("arc: PRECISION = %d.\n", peer->precision); } #endif up->saved_flags = pp->sloppyclockflag; } /* Note time of last believable timestamp. */ pp->lastrec = up->lastrec; #ifdef ARCRON_LEAPSECOND_KEEN /* Find out if a leap-second might just have happened... (ie is this the first hour of the first day of Jan or Jul?) */ if((pp->hour == 0) && (pp->day == 1) && ((month == 1) || (month == 7))) { if(possible_leap >= 0) { /* A leap may have happened, and no resync has started yet...*/ possible_leap = 1; } } else { /* Definitely not leap-second territory... */ possible_leap = 0; } #endif if (!refclock_process(pp)) { pp->lencode = 0; refclock_report(peer, CEVNT_BADTIME); return; } record_clock_stats(&peer->srcadr, pp->a_lastcode); refclock_receive(peer); } /* request_time() sends a time request to the clock with given peer. */ /* This automatically reports a fault if necessary. */ /* No data should be sent after this until arc_poll() returns. */ static void request_time (int, struct peer *); static void request_time( int unit, struct peer *peer ) { struct refclockproc *pp = peer->procptr; register struct arcunit *up = (struct arcunit *)pp->unitptr; #ifdef DEBUG if(debug) { printf("arc: unit %d: requesting time.\n", unit); } #endif if (!send_slow(up, pp->io.fd, "o\r")) { #ifdef DEBUG if (debug) { printf("arc: unit %d: problem sending", unit); } #endif pp->lencode = 0; refclock_report(peer, CEVNT_FAULT); return; } pp->polls++; } /* * arc_poll - called by the transmit procedure */ static void arc_poll( int unit, struct peer *peer ) { register struct arcunit *up; struct refclockproc *pp; int resync_needed; /* Should we start a resync? */ pp = peer->procptr; up = (struct arcunit *)pp->unitptr; #if 0 pp->lencode = 0; memset(pp->a_lastcode, 0, sizeof(pp->a_lastcode)); #endif #if 0 /* Flush input. */ tcflush(pp->io.fd, TCIFLUSH); #endif /* Resync if our next scheduled resync time is here or has passed. */ resync_needed = ( !(pp->sloppyclockflag & CLK_FLAG2) && (up->next_resync <= current_time) ); #ifdef ARCRON_LEAPSECOND_KEEN /* Try to catch a potential leap-second insertion or deletion quickly. In addition to the normal NTP fun of clocks that don't report leap-seconds spooking their hosts, this clock does not even sample the radio sugnal the whole time, so may miss a leap-second insertion or deletion for up to a whole sample time. To try to minimise this effect, if in the first few minutes of the day immediately following a leap-second-insertion point (ie in the first hour of the first day of the first and sixth months), and if the last resync was in the previous day, and a resync is not already in progress, resync the clock immediately. */ if((possible_leap > 0) && /* Must be 00:XX 01/0{1,7}/XXXX. */ (!up->resyncing)) { /* No resync in progress yet. */ resync_needed = 1; possible_leap = -1; /* Prevent multiple resyncs. */ msyslog(LOG_NOTICE,"ARCRON: unit %d: checking for leap second",unit); } #endif /* Do a resync if required... */ if(resync_needed) { /* First, reset quality value to `unknown' so we can detect */ /* when a quality message has been responded to by this */ /* being set to some other value. */ up->quality = QUALITY_UNKNOWN; /* Note that we are resyncing... */ up->resyncing = 1; /* Now actually send the resync command and an immediate poll. */ #ifdef DEBUG if(debug) { printf("arc: sending resync command (h\\r).\n"); } #endif msyslog(LOG_NOTICE, "ARCRON: unit %d: sending resync command", unit); send_slow(up, pp->io.fd, "h\r"); /* Schedule our next resync... */ up->next_resync = current_time + DEFAULT_RESYNC_TIME; /* Drop through to request time if appropriate. */ } /* If clock quality is too poor to trust, indicate a fault. */ /* If quality is QUALITY_UNKNOWN and ARCRON_KEEN is defined,*/ /* we'll cross our fingers and just hope that the thing */ /* synced so quickly we did not catch it---we'll */ /* double-check the clock is OK elsewhere. */ if( #ifdef ARCRON_KEEN (up->quality != QUALITY_UNKNOWN) && #else (up->quality == QUALITY_UNKNOWN) || #endif (up->quality < MIN_CLOCK_QUALITY_OK)) { #ifdef DEBUG if(debug) { printf("arc: clock quality %d too poor.\n", up->quality); } #endif pp->lencode = 0; refclock_report(peer, CEVNT_FAULT); return; } /* This is the normal case: request a timestamp. */ request_time(unit, peer); } #else int refclock_arc_bs; #endif