netdate/ 40755 144 144 0 6204405276 11440 5ustar florianusersnetdate/Makefile100644 144 144 312 6204405272 13145 0ustar florianusersLDFLAGS += -N CFLAGS = $(O) -Wall all: netdate netdate: netdate.o install: netdate install -s -m 0755 netdate /sbin/netdate install -m 0644 netdate.8 /usr/man/man8 clean: rm -f netdate *.o core netdate/netdate.8100644 144 144 12132 6204405272 13265 0ustar florianusers.TH NETDATE 8L 85/08/21 .UC 4 .SH NAME netdate \- set date and time by ARPA Internet RFC 868 .SH SYNOPSIS .B netdate [ \-v ] [ \-l limit ] [ protocol ] hostname... .SH DESCRIPTION \fINetdate\fP takes a list of names of Internet hosts as arguments, selects the one which supplies the best time, and sets the system time accordingly. The invoker must be the super-user for the time to be set. Protocol names (either \fBudp\fP or \fBtcp\fP) may be interspersed with the host names, and determine the protocol which will be used to connect to the hosts whose names follow, up to the next protocol name or the end of the arguments. The default protocol is \fBudp\fP. .PP The ``best'' time is chosen by polling the named hosts once each to find their times and taking their differences from the local host's time. These differences are used to find the largest group of hosts whose times agree with each other within a certain limit. The first host in the largest group is picked as the best host. (The assumption is that the hosts which are usually most accurate will be named first.) That host is polled again and the local host's time is set to the result. The chosen host's time is checked on this second poll to insure that its difference from the local host's time has not varied more than the limit from its difference at the first poll. .PP The default limit is five seconds. It may be set with the \fB\-l\fP option. The \fB\-v\fP option causes the groups to be shown. The host name \fBlocalhost\fP is recognized as a synonym for the name of the local host, no network connection is made for it, and its time difference is always zero. If \fBlocalhost\fP is chosen as having the best time, the system time will not be set. Hosts which do not respond are not counted in the groups. If the limit is set to zero, the time is set to that of the first host to respond and no other checking is done. Supplying only one host name argument also sets the limit to zero. .PP While the RFC868 protocol only returns 32\ bits of data, containing the time in seconds, \fInetdate\fP will accept an extra 32\ bits, containing microseconds (expected to be accurate to no more than milliseconds). Delays on long haul networks may make this extra precision useless, but it is useful on local area networks. The extra precision is not used on the first poll of a host, but it is used on the second poll of the chosen host, if that host supplies it. .SH EXAMPLE The most accurate hosts are named first in each example. Some such call on \fInetdate\fP should be put at the end of \fB/etc/rc.local\fP, so that the time will be set properly on system startup. It is also useful to have a shell script, e.g., \fB/etc/timehosts\fP, which contains a call on \fInetdate\fP with arguments appropriate to the local system, so that it is easy to set the time manually. .SH "netdate -l 30 udp dcn\-gateway tcp neighbor" \fIDcn\-gateway\fP is a hypothetical host which usually keeps time accurate to within milliseconds of Coordinated Universal Time, but may occasionally be eight hours off. \fINeighbor\fP is a neighbor of the local host which keeps time with moderate accuracy. The time will be set to that of \fIdcn\-gateway\fP if that and \fIneighbor\fP agree to within thirty seconds, else it will not be set at all. This is almost good enough for most circumstances, but won't do when the local host's time is known to be wrong (e.g., after a long downtime or a bad crash) and must be set to something. If one of the hosts named is inaccurate or not responding, there is a problem. .SH "netdate -l 30 udp dcn\-gateway tcp neighbor neighbor2" Only two of the three hosts named must agree on the time. The time will still be set (to that of the first neighbor), even if \fIdcn\-gateway\fP is far off as long as the two neighbors agree. This is probably good enough for most cases. One can arbitrarily gerrymander the vote for more insurance (and less clarity), as in the following example. .SH "netdate\ udp\ dcn\-gateway\ dcn1\ tcp\ bbn\-unix\ localhost\ neighbor" Here \fIdcn1\fP and \fIbbn\-unix\fP are more hypothetical very accurate timekeepers, at least one of which keeps time independently from \fIdcn\-gateway\fP, one hopes. It is very likely that the time will be set to that one of those three very accurate hosts, as long as at least two of them agree, or at least one of them agrees with the neighbor or the local host's time. If all the foreign hosts disagree, the time will not be set, since \fBlocalhost\fP will be chosen as best. .SH "netdate\ \-l\ 3\ localhost\ localhost\ udp\ dcn\-gateway\ dcn1\ tcp\ bbn\-unix" This example gives \fBlocalhost\fP two votes and declares it to usually have the most accurate time. All three foreign hosts must agree within three seconds and also differ from \fBlocalhosts\fP by more than three seconds for the time to be set. Thus the time will be set only if it really needs to be. .SH FILES .nf /etc/inet/services for the time service port number /etc/inet/protocols for the protocol numbers /etc/wtmp to record time-setting .SH SEE ALSO ARPANET Request for Comments 868, gettimeofday(2), date(1), WWV (USA): 2.5,5,10,15 MHz AM for Coordinated Universal Time (UCT). .SH DIAGNOSTICS netdate/netdate.c100644 144 144 30475 6204405272 13352 0ustar florianusers/* NO WARRANTY THERE IS NO WARRANTY FOR THIS PROGRAM, TO THE EXTENT PERMITTED BY APPLICABLE LAW. EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE PROGRAM IS WITH YOU. SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING, REPAIR OR CORRECTION. IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR REDISTRIBUTE THE PROGRAM, BE LIABLE TO YOU FOR DAMAGES, INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED TO LOSS OF DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. */ #ifndef lint char sccsid[]="@(#) netdate.c 1.16 85/08/21"; #endif #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #define WTMP "/etc/wtmp" struct utmp wtmp[2] = { { 0, 0, "|", "", 0, "", "", 0}, { 0, 0, "{", "", 0, "", "", 0} }; char *service = "time"; char *defaultproto = "udp"; /* difference between 1900 (RFC868) and 1970 (UNIX) base times */ #define NETBASE 2208988800 long limit = 5; #define MAXHOSTS 20 #define LOCALHOST "localhost" char *whoami; char hostname[65]; struct timeval now; struct timehost { char *hostname; short local; short bad; char *protoname; long protonumber; int socktype; struct timeval asked; struct timeval then; struct timeval acked; long difference; long count; } timehosts[MAXHOSTS]; struct timehost *tophost = &timehosts[MAXHOSTS]; void usage (void); int setproto (char *, struct timehost *); void main (int, char **); int getdiff (struct timehost *); int getdate (struct timehost *); void printit (struct timehost *); void tvsub (struct timeval *, struct timeval *, struct timeval *); void printdiff (char *, struct timeval *); void timeout (); static internettime (struct timehost *thishost); long getport (char *protoname); static int internettime (struct timehost *thishost); struct timehost *mungediffs(struct timehost *); void usage (void) { fprintf (stderr, "usage: %s [ -l limit ] host ...\n" "%s tries to find a group of at least two hosts whose times agree\n" "within %d seconds, and sets the time to that of the first host in the group.\n", whoami, whoami, limit); fprintf (stderr, "The limit may be set with the -l option. Setting it to zero (or supplying\n" "only one host name argument) will set the time to that of the first host to\n" "respond. The caller must be super-user for the system time to be set.\n"); exit (1); } int rdate = 0; int verbose = 0; int debug = 0; void main (int argc, char **argv) { extern char *rindex(); struct timehost *mungediffs(); register struct timehost *thishost; int hostargs = 0; if ((whoami = rindex(*argv, '/')) != NULL) whoami++; else whoami = *argv; if (strcmp (whoami, "rdate") == 0) { /* emulate SMI rdate command */ rdate = 1; defaultproto = "tcp"; limit = 0; } if (gethostname(hostname, (int)sizeof (hostname)) == -1) { perror ("gethostname"); exit (1); } while (*++argv != NULL && **argv == '-') { switch (argv[0][1]) { case 'd': debug++; break; case 'v': verbose++; break; case 'l': if (*++argv == NULL) usage(); limit = atoi(*argv); break; default: fprintf (stderr, "Unknown option: %s\n", *argv); usage(); break; } } if (*argv == NULL) usage(); if (debug) fprintf (stderr, "%s: rdate %d; verbose %d; limit %d.\n", whoami, rdate, verbose, limit); for (thishost = &timehosts[0]; *argv != NULL; argv++) { if (thishost >= tophost) { fprintf(stderr, "Too many hosts: ignoring"); do { fprintf (stderr, " %s", *argv); } while (*++argv != NULL); fprintf (stderr, "\n"); break; } if (setproto(*argv, thishost)) continue; thishost -> hostname = *argv; thishost -> bad = 0; if (strcmp (thishost -> hostname, LOCALHOST) == 0) thishost -> local = 1; if (++hostargs == 1 && argv[1] == NULL) /* Only one host arg, */ limit = 0; /* so just set to it. */ if (limit == 0) { if (!getdate(thishost)) continue; exit(0); } if (!getdiff (thishost)) continue; thishost++; } if (limit == 0) exit(1); if (thishost == &timehosts[0]) exit(1); if ((thishost = mungediffs(thishost)) == NULL) { fprintf (stderr, "No two hosts agree on the time within %d seconds\n", limit); exit(1); } if (!getdate (thishost)) exit (1); exit(0); } int setproto(char *what, struct timehost *thishost) { static char *protoname; static long protonumber; static int socktype; register struct protoent *pp; setprotoent(1); if ((pp = getprotobyname (what)) == NULL) { if (protoname == NULL) if (!setproto(defaultproto, thishost)) { fprintf(stderr, "Default protocol %s was not found in /etc/protocols.\n", defaultproto); exit(1); } thishost -> protoname = protoname; thishost -> protonumber = protonumber; thishost -> socktype = socktype; return(0); } protoname = what; /*pp -> p_name; this is static: don't use it.*/ protonumber = pp -> p_proto; switch (protonumber) { case IPPROTO_TCP: socktype = SOCK_STREAM; if (debug) fprintf(stderr, "%s SOCK_STREAM\n", protoname); break; case IPPROTO_UDP: socktype = SOCK_DGRAM; if (debug) fprintf(stderr, "%s SOCK_DGRAM\n", protoname); break; default: fprintf(stderr, "Unknown protocol: %s\n", protoname); exit(1); break; } return(1); } int getdiff(struct timehost *thishost) { if (!internettime (thishost)) return(0); thishost -> difference = thishost -> then.tv_sec - now.tv_sec; if (!rdate) printit(thishost); return(1); } /* Find the largest group of hosts which agree within the limit and return the first of that group. If no two hosts agree, give up. */ struct timehost * mungediffs(struct timehost *tophost) { register struct timehost *thishost, *ahost, *goodhost; long diff; tophost--; /* simplifies the comparisons */ goodhost = &timehosts[0]; for (thishost = &timehosts[0]; thishost < tophost; thishost++) { if (thishost -> bad) continue; thishost -> count = 1; if (verbose) printf ("%s", thishost -> hostname); for (ahost = thishost + 1; ahost <= tophost; ahost++) { if (thishost -> bad) continue; diff = ahost -> difference - thishost -> difference; if (abs(diff) < limit) { thishost -> count++; if (verbose) printf (" %s", ahost -> hostname); } } if (verbose) { printf (" %d\n", thishost -> count); (void)fflush(stdout); } if (thishost -> count > goodhost -> count) goodhost = thishost; } if (goodhost -> count > 1) return(goodhost); return(NULL); } int getdate (struct timehost *thishost) { int set = 0; if (!internettime (thishost)) return (0); if (thishost -> local) { printf ("Local host %s has best time, so not setting date\n", hostname); printit(thishost); exit(0); } if (limit != 0 && abs((thishost -> then.tv_sec - now.tv_sec) - thishost -> difference) > limit) { fprintf (stderr, "Time from %s has varied more than the limit of %d seconds\n", thishost -> hostname, limit); printit(thishost); exit(1); } if (settimeofday (&thishost -> then, (struct timezone *)0) == -1) perror ("netdate; settimeofday"); else { int wf; if ((wf = open(WTMP, 1)) >= 0) { wtmp[0].ut_time = now.tv_sec; wtmp[1].ut_time = thishost -> then.tv_sec; (void)lseek(wf, 0L, 2); (void)write(wf, (char *)wtmp, sizeof(wtmp)); (void)close(wf); } set = 1; } printit(thishost); return(set); } void printit(struct timehost *thishost) { extern char *ctime(); struct tm *tp, *localtime(); struct timeval diff; char newstring[128]; if (rdate) printf ("%s", ctime((unsigned long *)&thishost -> then.tv_sec)); else { (void)sprintf(newstring, "%s ", thishost -> hostname); tvsub(&diff, &thishost -> then, &now); printdiff(&newstring[strlen(newstring)], &diff); printf ("%-24s %.19s.%03d", newstring, ctime((unsigned long *)&thishost -> then.tv_sec), thishost -> then.tv_usec / 1000); if (verbose) { tp = localtime((unsigned long *)&thishost -> acked); printf(" at %02d:%02d:%02d.%03d", tp -> tm_hour, tp -> tm_min, tp -> tm_sec, thishost -> acked.tv_usec / 1000); tvsub(&diff, &thishost -> acked, &thishost -> asked); printdiff(newstring, &diff); printf(" delay %s", newstring); } printf("\n"); } (void)fflush (stdout); } void tvsub(tdiff, t1, t0) struct timeval *tdiff, *t1, *t0; { tdiff->tv_sec = t1->tv_sec - t0->tv_sec; tdiff->tv_usec = t1->tv_usec - t0->tv_usec; if (tdiff->tv_sec < 0 && tdiff->tv_usec > 0) tdiff->tv_sec++, tdiff->tv_usec -= 1000000; if (tdiff->tv_sec > 0 && tdiff->tv_usec < 0) tdiff->tv_sec--, tdiff->tv_usec += 1000000; } void printdiff(char *where, struct timeval *diff) { (void) sprintf (where, "%c%d.%.03d", (diff->tv_sec < 0 || diff->tv_usec < 0) ? '-' : '+', abs(diff->tv_sec), abs(diff->tv_usec) / 1000); } static jmp_buf jb; void timeout() { longjmp(jb, 1); } static int internettime (struct timehost *thishost) { register struct hostent *hp; struct sockaddr_in sin; long port; int nread; static int s = -1; if (thishost -> local) { if (gettimeofday (&now, (struct timezone *)0) == -1) { perror ("netdate: gettimeofday"); exit (1); } thishost -> asked = now; thishost -> then = now; thishost -> acked = now; return(1); } timerclear(&thishost -> then); if (setjmp(jb)) goto bad; (void)signal(SIGALRM, timeout); if (s != -1) (void) close (s), s = -1; port = getport(thishost -> protoname); bzero((char *)&sin, sizeof (sin)); sethostent(1); if ((hp = gethostbyname(thishost -> hostname)) == NULL) { fprintf(stderr, "%s: %s: unknown host\n", whoami, thishost -> hostname); goto out; } sin.sin_family = hp->h_addrtype; (void)alarm(20); s = socket(hp->h_addrtype, thishost -> socktype, 0 /*protonumber*/); if (s < 0) { perror("netdate: socket"); (void)alarm(0); goto out; } if (thishost -> socktype == SOCK_STREAM) { if (bind(s, (struct sockaddr *)&sin, sizeof (sin)) < 0) { perror("netdate: bind"); goto bad; } } bcopy(hp->h_addr, (char *)&sin.sin_addr, hp->h_length); sin.sin_port = port; (void)gettimeofday (&thishost -> asked, (struct timezone *)0); if (connect(s, (struct sockaddr *)&sin, sizeof (sin)) < 0) { perror("netdate: connect"); goto bad; } if (thishost -> socktype == SOCK_DGRAM) { if (write (s, "\n", 1) < 0) { perror ("netdate: send"); goto bad; } } nread = read (s, (char *)&thishost -> then, sizeof (thishost -> then)); (void)gettimeofday (&thishost -> acked, (struct timezone *)0); (void)alarm(0); now = thishost -> acked; if (nread < sizeof(thishost -> then.tv_sec)) { perror ("netdate: read"); goto bad; } /* RFC 868 only allows seconds, but what the hell */ if (nread == sizeof(thishost -> then)) thishost -> then.tv_usec = ntohl(thishost -> then.tv_usec); else thishost -> then.tv_usec = 0L; thishost -> then.tv_sec = ntohl (thishost -> then.tv_sec) - NETBASE; return (1); /* don't close before returning to avoid delays */ bad: (void)alarm(0); (void) close (s), s = -1; out: if (gettimeofday (&now, (struct timezone *)0) == -1) { perror ("netdate: gettimeofday"); exit (1); } thishost -> asked = now; thishost -> then = now; thishost -> acked = now; thishost -> bad = 1; fprintf (stderr, "Connection with %s to %s failed.\n", thishost -> protoname, thishost -> hostname); return(0); } long getport(char *protoname) { register struct servent *sp; static long port; if (port != 0) return(port); if ((sp = getservbyname(service, protoname)) == 0) { fprintf(stderr, "%s: %s/%s: unknown service\n", whoami, service, protoname); exit(1); } return (port = sp->s_port); } netdate/COPYRIGHT100644 144 144 2646 6006404513 13031 0ustar florianusers/* NO WARRANTY THERE IS NO WARRANTY FOR THIS PROGRAM, TO THE EXTENT PERMITTED BY APPLICABLE LAW. EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE PROGRAM IS WITH YOU. SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL NECESSARY SERVICING, REPAIR OR CORRECTION. IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR REDISTRIBUTE THE PROGRAM, BE LIABLE TO YOU FOR DAMAGES, INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED TO LOSS OF DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. */ This program has been released to the public domain and can be used by anyone who wants to. The original sources can be found on the Simtel source CD.