miscutils/adjtimex.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * adjtimex.c - read, and possibly modify, the Linux kernel 'timex' variables.
   4  *
   5  * Originally written: October 1997
   6  * Last hack: March 2001
   7  * Copyright 1997, 2000, 2001 Larry Doolittle <LRDoolittle@lbl.gov>
   8  *
   9  * busyboxed 20 March 2001, Larry Doolittle <ldoolitt@recycle.lbl.gov>
  10  *
  11  * Licensed under GPLv2 or later, see file LICENSE in this source tree.
  12  */
  13 //config:config ADJTIMEX
  14 //config:       bool "adjtimex (4.9 kb)"
  15 //config:       default y
  16 //config:       help
  17 //config:       Adjtimex reads and optionally sets adjustment parameters for
  18 //config:       the Linux clock adjustment algorithm.
  19
  20 //applet:IF_ADJTIMEX(APPLET_NOFORK(adjtimex, adjtimex, BB_DIR_SBIN, BB_SUID_DROP, adjtimex))
  21
  22 //kbuild:lib-$(CONFIG_ADJTIMEX) += adjtimex.o
  23
  24 //usage:#define adjtimex_trivial_usage
  25 //usage:       "[-q] [-o OFS] [-f FREQ] [-p TCONST] [-t TICK]"
  26 //usage:#define adjtimex_full_usage "\n\n"
  27 //usage:       "Read or set kernel time variables. See adjtimex(2)\n"
  28 //usage:     "\n        -q      Quiet"
  29 //usage:     "\n        -o OFF  Time offset, microseconds"
  30 //usage:     "\n        -f FREQ Frequency adjust, integer kernel units (65536 is 1ppm)"
  31 //usage:     "\n        -t TICK Microseconds per tick, usually 10000"
  32 //usage:     "\n                (positive -t or -f values make clock run faster)"
  33 //usage:     "\n        -p TCONST"
  34
  35 #include "libbb.h"
  36 #ifdef __BIONIC__
  37 # include <linux/timex.h>
  38 #else
  39 # include <sys/timex.h>
  40 #endif
  41
  42 static const uint16_t statlist_bit[] ALIGN2 = {
  43         STA_PLL,
  44         STA_PPSFREQ,
  45         STA_PPSTIME,
  46         STA_FLL,
  47         STA_INS,
  48         STA_DEL,
  49         STA_UNSYNC,
  50         STA_FREQHOLD,
  51         STA_PPSSIGNAL,
  52         STA_PPSJITTER,
  53         STA_PPSWANDER,
  54         STA_PPSERROR,
  55         STA_CLOCKERR,
  56         0
  57 };
  58 static const char statlist_name[] ALIGN1 =
  59         "PLL"       "\0"
  60         "PPSFREQ"   "\0"
  61         "PPSTIME"   "\0"
  62         "FFL"       "\0"
  63         "INS"       "\0"
  64         "DEL"       "\0"
  65         "UNSYNC"    "\0"
  66         "FREQHOLD"  "\0"
  67         "PPSSIGNAL" "\0"
  68         "PPSJITTER" "\0"
  69         "PPSWANDER" "\0"
  70         "PPSERROR"  "\0"
  71         "CLOCKERR"
  72 ;
  73
  74 static const char ret_code_descript[] ALIGN1 =
  75         "clock synchronized" "\0"
  76         "insert leap second" "\0"
  77         "delete leap second" "\0"
  78         "leap second in progress" "\0"
  79         "leap second has occurred" "\0"
  80         "clock not synchronized"
  81 ;
  82
  83 int adjtimex_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
  84 int adjtimex_main(int argc UNUSED_PARAM, char **argv)
  85 {
  86         enum {
  87                 OPT_quiet = 0x1
  88         };
  89         unsigned opt;
  90         char *opt_o, *opt_f, *opt_p, *opt_t;
  91         struct timex txc;
  92         int ret;
  93         const char *descript;
  94
  95         memset(&txc, 0, sizeof(txc));
  96
  97         opt = getopt32(argv, "^" "qo:f:p:t:"
  98                         "\0" "=0"/*no valid non-option args*/,
  99                         &opt_o, &opt_f, &opt_p, &opt_t
 100         );
 101         //if (opt & 0x1) // -q
 102         if (opt & 0x2) { // -o
 103                 txc.offset = xatol(opt_o);
 104                 txc.modes |= ADJ_OFFSET_SINGLESHOT;
 105         }
 106         if (opt & 0x4) { // -f
 107                 txc.freq = xatol(opt_f);
 108                 txc.modes |= ADJ_FREQUENCY;
 109         }
 110         if (opt & 0x8) { // -p
 111                 txc.constant = xatol(opt_p);
 112                 txc.modes |= ADJ_TIMECONST;
 113         }
 114         if (opt & 0x10) { // -t
 115                 txc.tick = xatol(opt_t);
 116                 txc.modes |= ADJ_TICK;
 117         }
 118
 119         /* It's NOFORK applet because the code is very simple:
 120          * just some printf. No opens, no allocs.
 121          * If you need to make it more complex, feel free to downgrade to NOEXEC
 122          */
 123
 124         ret = adjtimex(&txc);
 125         if (ret < 0)
 126                 bb_perror_nomsg_and_die();
 127
 128         if (!(opt & OPT_quiet)) {
 129                 const char *sep;
 130                 const char *name;
 131                 int i;
 132
 133                 printf(
 134                         "    mode:         %d\n"
 135                         "-o  offset:       %ld us\n"
 136                         "-f  freq.adjust:  %ld (65536 = 1ppm)\n"
 137                         "    maxerror:     %ld\n"
 138                         "    esterror:     %ld\n"
 139                         "    status:       %d (",
 140                         txc.modes, txc.offset, txc.freq, txc.maxerror,
 141                         txc.esterror, txc.status
 142                 );
 143
 144                 /* representative output of next code fragment:
 145                  * "PLL | PPSTIME"
 146                  */
 147                 name = statlist_name;
 148                 sep = "";
 149                 for (i = 0; statlist_bit[i]; i++) {
 150                         if (txc.status & statlist_bit[i]) {
 151                                 printf("%s%s", sep, name);
 152                                 sep = " | ";
 153                         }
 154                         name += strlen(name) + 1;
 155                 }
 156
 157                 descript = "error";
 158                 if (ret <= 5)
 159                         descript = nth_string(ret_code_descript, ret);
 160                 printf(")\n"
 161                         "-p  timeconstant: %ld\n"
 162                         "    precision:    %ld us\n"
 163                         "    tolerance:    %ld\n"
 164                         "-t  tick:         %ld us\n"
 165                         "    time.tv_sec:  %ld\n"
 166                         "    time.tv_usec: %ld\n"
 167                         "    return value: %d (%s)\n",
 168                         txc.constant,
 169                         txc.precision, txc.tolerance, txc.tick,
 170                         (long)txc.time.tv_sec, (long)txc.time.tv_usec,
 171                         ret, descript
 172                 );
 173         }
 174
 175         return 0;
 176 }