| 1 | /* |
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| 2 | * $Source: /afs/dev.mit.edu/source/repository/athena/etc/gettime/gettime.c,v $ |
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| 3 | * $Author: builder $ |
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| 4 | * $Locker: $ |
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| 5 | * $Header: /afs/dev.mit.edu/source/repository/athena/etc/gettime/gettime.c,v 1.1 1985-05-27 16:17:18 builder Exp $ |
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| 6 | */ |
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| 7 | |
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| 8 | #ifndef lint |
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| 9 | static char *rcsid_gettime_c = "$Header: /afs/dev.mit.edu/source/repository/athena/etc/gettime/gettime.c,v 1.1 1985-05-27 16:17:18 builder Exp $"; |
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| 10 | #endif lint |
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| 11 | |
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| 12 | #include <sys/types.h> |
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| 13 | #include <sys/time.h> |
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| 14 | #include <sys/socket.h> |
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| 15 | #include <netinet/in.h> |
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| 16 | #include <stdio.h> |
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| 17 | #include <errno.h> |
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| 18 | #include <netdb.h> |
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| 19 | #include <signal.h> |
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| 20 | #include <setjmp.h> |
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| 21 | char buffer[512]; |
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| 22 | char *ctime(); |
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| 23 | struct timeval tv; |
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| 24 | struct timezone tz; |
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| 25 | jmp_buf top_level; |
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| 26 | int hiccup(); |
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| 27 | main(argc, argv) |
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| 28 | int argc; |
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| 29 | char *argv[]; |
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| 30 | { |
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| 31 | struct sockaddr_in sin; |
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| 32 | struct servent *sp; |
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| 33 | struct hostent *host; |
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| 34 | int setflg = 0; |
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| 35 | register int i; |
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| 36 | register int s; |
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| 37 | long hosttime; |
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| 38 | register int *nettime; |
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| 39 | char hostname[64]; |
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| 40 | int attempts = 0; |
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| 41 | strcpy (hostname, "dcn1"); |
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| 42 | for (i = 1;i < argc;i++) { |
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| 43 | if (*argv[i] == '-') { |
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| 44 | if (argv[i][1] == 's') setflg++; |
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| 45 | else { |
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| 46 | fprintf (stderr, "%s: Invalid argument %s\n", |
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| 47 | argv[0], argv[i]); |
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| 48 | exit (11); |
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| 49 | } |
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| 50 | } |
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| 51 | else strcpy (hostname, argv[i]); |
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| 52 | } |
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| 53 | sp = getservbyname("time", "udp"); |
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| 54 | if (sp == 0) { |
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| 55 | fprintf (stderr, "%s: time/udp: unknown service.\n", |
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| 56 | argv[0]); |
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| 57 | exit (1); |
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| 58 | } |
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| 59 | host = gethostbyname(hostname); |
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| 60 | if (host == NULL) { |
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| 61 | fprintf (stderr, "%s: The timeserver host %s is unknown\n", |
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| 62 | argv[0], hostname); |
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| 63 | exit (2); |
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| 64 | } |
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| 65 | sin.sin_family = host->h_addrtype; |
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| 66 | bcopy (host->h_addr, (caddr_t)&sin.sin_addr, |
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| 67 | host->h_length); |
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| 68 | sin.sin_port = sp->s_port; |
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| 69 | s = socket(AF_INET, SOCK_DGRAM, 0); |
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| 70 | if (s < 0) { |
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| 71 | perror ("gettime: socket"); |
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| 72 | exit (3); |
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| 73 | } |
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| 74 | if (connect (s, (caddr_t)&sin, sizeof (sin)) < 0) { |
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| 75 | perror ("gettime: connect"); |
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| 76 | exit (4); |
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| 77 | } |
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| 78 | setjmp(top_level); |
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| 79 | if (attempts++ > 5) { |
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| 80 | close (s); |
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| 81 | fprintf (stderr, "Failed to get time from %s\n", |
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| 82 | hostname); |
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| 83 | exit (10); |
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| 84 | } |
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| 85 | alarm(0); |
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| 86 | signal(SIGALRM, hiccup); |
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| 87 | alarm(5); |
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| 88 | send (s, buffer, 40, 0); /* Send an empty packet */ |
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| 89 | if (gettimeofday (&tv, &tz) < 0) { |
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| 90 | perror ("gettime: gettimeofday"); |
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| 91 | exit (5); |
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| 92 | } |
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| 93 | recv (s, buffer, 512, 0); /* Wait for the reply */ |
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| 94 | nettime = (int *)buffer; |
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| 95 | hosttime = (long) ntohl (*nettime) - 2208988800; |
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| 96 | fprintf (stdout, "%s", ctime(&hosttime)); |
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| 97 | (&tv)->tv_sec = hosttime; |
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| 98 | if (setflg) { |
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| 99 | if (settimeofday (&tv, &tz) < 0) { |
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| 100 | perror ("gettime: settimeofday"); |
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| 101 | exit (6); |
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| 102 | } |
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| 103 | } |
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| 104 | close (s); |
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| 105 | exit (0); |
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| 106 | } |
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| 107 | hiccup() { |
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| 108 | longjmp (top_level); |
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| 109 | } |
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