xref: /netbsd-src/external/bsd/ntp/dist/util/timetrim.c (revision cdfa2a7ef92791ba9db70a584a1d904730e6fb46)
1 /*	$NetBSD: timetrim.c,v 1.5 2020/05/25 20:47:37 christos Exp $	*/
2 
3 #if defined(sgi) || defined(_UNICOSMP)
4 /*
5  * timetrim.c
6  *
7  * "timetrim" allows setting and adjustment of the system clock frequency
8  * trim parameter on Silicon Graphics machines.  The trim value native
9  * units are nanoseconds per second (10**-9), so a trim value of 1 makes
10  * the system clock step ahead 1 nanosecond more per second than a value
11  * of zero.  Xntpd currently uses units of 2**-20 secs for its frequency
12  * offset (drift) values; to convert to a timetrim value, multiply by
13  * 1E9 / 2**20 (about 954).
14  *
15  * "timetrim" with no arguments just prints out the current kernel value.
16  * With a numeric argument, the kernel value is set to the supplied value.
17  * The "-i" flag causes the supplied value to be added to the kernel value.
18  * The "-n" option causes all input and output to be in xntpd units rather
19  * than timetrim native units.
20  *
21  * Note that there is a limit of +-3000000 (0.3%) on the timetrim value
22  * which is (silently?) enforced by the kernel.
23  *
24  */
25 
26 #ifdef HAVE_CONFIG_H
27 #include <config.h>
28 #endif
29 
30 #include <stdio.h>
31 #include <ctype.h>
32 #include <stdlib.h>
33 #ifdef HAVE_SYS_SYSSGI_H
34 # include <sys/syssgi.h>
35 #endif
36 #ifdef HAVE_SYS_SYSTUNE_H
37 # include <sys/systune.h>
38 #endif
39 
40 #define abs(X) (((X) < 0) ? -(X) : (X))
41 #define USAGE "usage: timetrim [-n] [[-i] value]\n"
42 #define SGITONTP(X) ((double)(X) * 1048576.0/1.0e9)
43 #define NTPTOSGI(X) ((long)((X) * 1.0e9/1048576.0))
44 
45 int
main(int argc,char * argv[])46 main(
47 	int argc,
48 	char *argv[]
49 	)
50 {
51 	char *rem;
52 	int incremental = 0, ntpunits = 0;
53 	long timetrim;
54 	double value;
55 
56 	while (--argc && **++argv == '-' && isalpha((int)argv[0][1])) {
57 		switch (argv[0][1]) {
58 		    case 'i':
59 			incremental++;
60 			break;
61 		    case 'n':
62 			ntpunits++;
63 			break;
64 		    default:
65 			fprintf(stderr, USAGE);
66 			exit(1);
67 		}
68 	}
69 
70 #ifdef HAVE_SYS_SYSSGI_H
71 	if (syssgi(SGI_GETTIMETRIM, &timetrim) < 0) {
72 		perror("syssgi");
73 		exit(2);
74 	}
75 #endif
76 #ifdef HAVE_SYS_SYSTUNE_H
77 	if (systune(SYSTUNE_GET, "timetrim", &timetrim) < 0) {
78 		perror("systune");
79 		exit(2);
80 	}
81 #endif
82 
83 	if (argc == 0) {
84 		if (ntpunits)
85 		    fprintf(stdout, "%0.5f\n", SGITONTP(timetrim));
86 		else
87 		    fprintf(stdout, "%ld\n", timetrim);
88 	} else if (argc != 1) {
89 		fprintf(stderr, USAGE);
90 		exit(1);
91 	} else {
92 		value = strtod(argv[0], &rem);
93 		if (*rem != '\0') {
94 			fprintf(stderr, USAGE);
95 			exit(1);
96 		}
97 		if (ntpunits)
98 		    value = NTPTOSGI(value);
99 		if (incremental)
100 		    timetrim += value;
101 		else
102 		    timetrim = value;
103 #ifdef HAVE_SYS_SYSSGI_H
104 		if (syssgi(SGI_SETTIMETRIM, timetrim) < 0) {
105 			perror("syssgi");
106 			exit(2);
107 		}
108 #endif
109 #ifdef HAVE_SYS_SYSTUNE_H
110 		if (systune(SYSTUNE_SET, "timer", "timetrim", &timetrim) < 0) {
111 			perror("systune");
112 			exit(2);
113 		}
114 #endif
115 	}
116 	return 0;
117 }
118 #endif
119