1 /* vi: set sw=4 ts=4: */
3 * adjtimex.c - read, and possibly modify, the Linux kernel 'timex' variables.
5 * Originally written: October 1997
6 * Last hack: March 2001
7 * Copyright 1997, 2000, 2001 Larry Doolittle <LRDoolittle@lbl.gov>
9 * busyboxed 20 March 2001, Larry Doolittle <ldoolitt@recycle.lbl.gov>
11 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
13 //config:config ADJTIMEX
14 //config: bool "adjtimex (4.7 kb)"
16 //config: select PLATFORM_LINUX
18 //config: Adjtimex reads and optionally sets adjustment parameters for
19 //config: the Linux clock adjustment algorithm.
21 //applet:IF_ADJTIMEX(APPLET_NOFORK(adjtimex, adjtimex, BB_DIR_SBIN, BB_SUID_DROP, adjtimex))
23 //kbuild:lib-$(CONFIG_ADJTIMEX) += adjtimex.o
25 //usage:#define adjtimex_trivial_usage
26 //usage: "[-q] [-o OFF] [-f FREQ] [-p TCONST] [-t TICK]"
27 //usage:#define adjtimex_full_usage "\n\n"
28 //usage: "Read or set kernel time variables. See adjtimex(2)\n"
29 //usage: "\n -q Quiet"
30 //usage: "\n -o OFF Time offset, microseconds"
31 //usage: "\n -f FREQ Frequency adjust, integer kernel units (65536 is 1ppm)"
32 //usage: "\n -t TICK Microseconds per tick, usually 10000"
33 //usage: "\n (positive -t or -f values make clock run faster)"
34 //usage: "\n -p TCONST"
38 # include <linux/timex.h>
40 # include <sys/timex.h>
43 static const uint16_t statlist_bit[] ALIGN2 = {
59 static const char statlist_name[] ALIGN1 =
75 static const char ret_code_descript[] ALIGN1 =
76 "clock synchronized" "\0"
77 "insert leap second" "\0"
78 "delete leap second" "\0"
79 "leap second in progress" "\0"
80 "leap second has occurred" "\0"
81 "clock not synchronized"
84 int adjtimex_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
85 int adjtimex_main(int argc UNUSED_PARAM, char **argv)
91 char *opt_o, *opt_f, *opt_p, *opt_t;
96 memset(&txc, 0, sizeof(txc));
98 opt = getopt32(argv, "^" "qo:f:p:t:"
99 "\0" "=0"/*no valid non-option args*/,
100 &opt_o, &opt_f, &opt_p, &opt_t
102 //if (opt & 0x1) // -q
103 if (opt & 0x2) { // -o
104 txc.offset = xatol(opt_o);
105 txc.modes |= ADJ_OFFSET_SINGLESHOT;
107 if (opt & 0x4) { // -f
108 txc.freq = xatol(opt_f);
109 txc.modes |= ADJ_FREQUENCY;
111 if (opt & 0x8) { // -p
112 txc.constant = xatol(opt_p);
113 txc.modes |= ADJ_TIMECONST;
115 if (opt & 0x10) { // -t
116 txc.tick = xatol(opt_t);
117 txc.modes |= ADJ_TICK;
120 /* It's NOFORK applet because the code is very simple:
121 * just some printf. No opens, no allocs.
122 * If you need to make it more complex, feel free to downgrade to NOEXEC
125 ret = adjtimex(&txc);
127 bb_perror_nomsg_and_die();
129 if (!(opt & OPT_quiet)) {
136 "-o offset: %ld us\n"
137 "-f freq.adjust: %ld (65536 = 1ppm)\n"
141 txc.modes, txc.offset, txc.freq, txc.maxerror,
142 txc.esterror, txc.status
145 /* representative output of next code fragment:
148 name = statlist_name;
150 for (i = 0; statlist_bit[i]; i++) {
151 if (txc.status & statlist_bit[i]) {
152 printf("%s%s", sep, name);
155 name += strlen(name) + 1;
160 descript = nth_string(ret_code_descript, ret);
162 "-p timeconstant: %ld\n"
163 " precision: %ld us\n"
166 " time.tv_sec: %ld\n"
167 " time.tv_usec: %ld\n"
168 " return value: %d (%s)\n",
170 txc.precision, txc.tolerance, txc.tick,
171 (long)txc.time.tv_sec, (long)txc.time.tv_usec,