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ntpclient.c
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ntpclient.c
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/* NTP client
*
* Copyright (C) 1997-2015 Larry Doolittle <larry@doolittle.boa.org>
* Copyright (C) 2010-2018 Joachim Nilsson <troglobit@gmail.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License (Version 2,
* June 1991) as published by the Free Software Foundation. At the
* time of writing, that license was published by the FSF with the URL
* http://www.gnu.org/copyleft/gpl.html, and is incorporated herein by
* reference.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
/*
* Possible future improvements:
* - Support leap second processing
* - Support multiple (interleaved) servers
*
* If the compile gives you any flak, check below in the section
* labelled "XXX fixme - non-automatic build configuration".
*/
#include <config.h>
#include <stdio.h>
#include <stdint.h>
#include <stdlib.h>
#include <signal.h>
#include <string.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netdb.h> /* getaddrinfo -> gethostbyname */
#include <arpa/inet.h>
#include <time.h>
#include <unistd.h>
#include <errno.h>
#ifdef PRECISION_SIOCGSTAMP
#include <sys/ioctl.h>
#endif
#ifdef USE_OBSOLETE_GETTIMEOFDAY
#include <sys/time.h>
#endif
#include "ntpclient.h"
/* XXX fixme - non-automatic build configuration */
#ifdef __linux__
#include <sys/utsname.h>
#include <sys/time.h>
#include <sys/timex.h>
#else
extern struct hostent *gethostbyname(const char *name);
extern int h_errno;
char __hstrerror_buf[10];
#define hstrerror(errnum) \
snprintf(__hstrerror_buf, sizeof(__hstrerror_buf), "Error %d", errnum)
#endif
/* Default to the RFC-4330 specified value */
#ifndef MIN_INTERVAL
#define MIN_INTERVAL 15
#endif
#ifdef ENABLE_REPLAY
#define REPLAY_OPTION "r"
#else
#define REPLAY_OPTION
#endif
#define JAN_1970 0x83aa7e80 /* 2208988800 1970 - 1900 in seconds */
#define NTP_PORT (123)
/* How to multiply by 4294.967296 quickly (and not quite exactly)
* without using floating point or greater than 32-bit integers.
* If you want to fix the last 12 microseconds of error, add in
* (2911*(x))>>28)
*/
#define NTPFRAC(x) ( 4294*(x) + ( (1981*(x))>>11 ) )
/* The reverse of the above, needed if we want to set our microsecond
* clock (via clock_settime) based on the incoming time in NTP format.
* Basically exact.
*/
#define USEC(x) ( ( (x) >> 12 ) - 759 * ( ( ( (x) >> 10 ) + 32768 ) >> 16 ) )
/* Converts NTP delay and dispersion, apparently in seconds scaled
* by 65536, to microseconds. RFC-1305 states this time is in seconds,
* doesn't mention the scaling.
* Should somehow be the same as 1000000 * x / 65536
*/
#define sec2u(x) ( (x) * 15.2587890625 )
struct ntptime {
unsigned int coarse;
unsigned int fine;
};
struct ntp_control {
uint32_t time_of_send[2];
int usermode;
int live;
int set_clock; /* non-zero presumably needs root privs */
int probe_count;
int cycle_time;
int goodness;
int cross_check;
uint16_t local_udp_port;
char *server; /* must be set */
char serv_addr[4];
};
int debug = 0;
int verbose = 0; /* Verbose flag, produce useful output to log */
int log_enable = 0;
int log_level = LOG_NOTICE;
const char *prognm = PACKAGE_NAME;
static int sighup = 0;
static int sigterm = 0;
extern char *optarg; /* according to man 2 getopt */
/* prototypes for some local routines */
static void send_packet(int usd, uint32_t time_sent[2]);
static int rfc1305print(uint32_t *data, struct ntptime *arrival, struct ntp_control *ntpc, int *error);
static int getaddrbyname(char *host, struct sockaddr_storage *ss);
void logit(int severity, int syserr, const char *format, ...)
{
va_list ap;
char buf[200];
if (log_level < severity)
return;
va_start(ap, format);
vsnprintf(buf, sizeof(buf), format, ap);
va_end(ap);
#ifdef ENABLE_SYSLOG
if (log_enable > 0) {
if (syserr)
syslog(severity, "%s: %s", buf, strerror(syserr));
else
syslog(severity, "%s", buf);
return;
}
#endif
if (severity == LOG_WARNING)
fputs("Warning - ", stderr);
else if (severity == LOG_ERR)
fputs("ERROR - ", stderr);
if (syserr)
fprintf(stderr, "%s: %s\n", buf, strerror(errno));
else
fprintf(stderr, "%s\n", buf);
}
/* OS dependent routine to get the current value of clock frequency */
static int get_current_freq(void)
{
#ifdef __linux__
struct timex txc;
txc.modes = 0;
if (adjtimex(&txc) < 0) {
logit(LOG_ERR, errno, "Failed adjtimex(GET)");
exit(1);
}
return txc.freq;
#else
return 0;
#endif
}
/* OS dependent routine to set a new value of clock frequency */
static int set_freq(int new_freq)
{
#ifdef __linux__
struct timex txc;
txc.modes = ADJ_FREQUENCY;
txc.freq = new_freq;
if (adjtimex(&txc) < 0) {
logit(LOG_ERR, errno, "Failed adjtimex(SET)");
exit(1);
}
return txc.freq;
#else
return 0;
#endif
}
static void set_time(struct ntptime *new)
{
#ifndef USE_OBSOLETE_GETTIMEOFDAY
/* POSIX 1003.1-2001 way to set the system clock */
struct timespec tv_set;
/* it would be even better to subtract half the slop */
tv_set.tv_sec = new->coarse - JAN_1970;
/* divide xmttime.fine by 4294.967296 */
tv_set.tv_nsec = USEC(new->fine) * 1000;
if (clock_settime(CLOCK_REALTIME, &tv_set) < 0) {
logit(LOG_ERR, errno, "Failed clock_settime()");
exit(1);
}
if (debug)
logit(LOG_DEBUG, 0, "Set time to %lu.%.9lu", tv_set.tv_sec, tv_set.tv_nsec);
#else
/* Traditional Linux way to set the system clock */
struct timeval tv_set;
/* it would be even better to subtract half the slop */
tv_set.tv_sec = new->coarse - JAN_1970;
/* divide xmttime.fine by 4294.967296 */
tv_set.tv_usec = USEC(new->fine);
if (settimeofday(&tv_set, NULL) < 0) {
logit(LOG_ERR, errno, "Failed settimeofday()");
exit(1);
}
if (debug)
logit(LOG_DEBUG, 0, "Set time to %lu.%.6lu", tv_set.tv_sec, tv_set.tv_usec);
#endif
}
static void ntpc_gettime(uint32_t *time_coarse, uint32_t *time_fine)
{
#ifndef USE_OBSOLETE_GETTIMEOFDAY
/* POSIX 1003.1-2001 way to get the system time */
struct timespec now;
clock_gettime(CLOCK_REALTIME, &now);
*time_coarse = now.tv_sec + JAN_1970;
*time_fine = NTPFRAC(now.tv_nsec / 1000);
#else
/* Traditional Linux way to get the system time */
struct timeval now;
gettimeofday(&now, NULL);
*time_coarse = now.tv_sec + JAN_1970;
*time_fine = NTPFRAC(now.tv_usec);
#endif
}
static void send_packet(int usd, uint32_t time_sent[2])
{
uint32_t data[12];
#define LI 0
#define VN 3
#define MODE 3
#define STRATUM 0
#define POLL 4
#define PREC -6
#ifdef ENABLE_DEBUG
if (debug)
logit(LOG_DEBUG, 0, "Sending packet ...");
#endif
if (sizeof(data) != 48) {
logit(LOG_ERR, 0, "Packet size error");
return;
}
memset(data, 0, sizeof data);
data[0] = htonl((LI << 30) | (VN << 27) | (MODE << 24) | (STRATUM << 16) | (POLL << 8) | (PREC & 0xff));
data[1] = htonl(1 << 16); /* Root Delay (seconds) */
data[2] = htonl(1 << 16); /* Root Dispersion (seconds) */
ntpc_gettime(time_sent, time_sent + 1);
data[10] = htonl(time_sent[0]); /* Transmit Timestamp coarse */
data[11] = htonl(time_sent[1]); /* Transmit Timestamp fine */
send(usd, data, 48, 0);
}
static void get_packet_timestamp(int usd, struct ntptime *udp_arrival_ntp)
{
#ifdef PRECISION_SIOCGSTAMP
struct timeval udp_arrival;
if (ioctl(usd, SIOCGSTAMP, &udp_arrival) < 0) {
logit(LOG_ERR, errno, "Failed ioctl(SIOCGSTAMP)");
ntpc_gettime(&udp_arrival_ntp->coarse, &udp_arrival_ntp->fine);
} else {
udp_arrival_ntp->coarse = udp_arrival.tv_sec + JAN_1970;
udp_arrival_ntp->fine = NTPFRAC(udp_arrival.tv_usec);
}
#else
(void)usd; /* not used */
ntpc_gettime(&udp_arrival_ntp->coarse, &udp_arrival_ntp->fine);
#endif
}
static int check_source(int data_len, struct sockaddr_storage *sa_source, struct ntp_control *ntpc)
{
struct sockaddr_in6 *ipv6;
struct sockaddr_in *ipv4;
uint16_t port;
(void)data_len;
(void)ntpc; /* not used */
logit(LOG_DEBUG, 0, "packet of length %d received", data_len);
if (sa_source->ss_family == AF_INET) {
ipv4 = (struct sockaddr_in *)(sa_source);
port = ntohs(ipv4->sin_port);
} else if (sa_source->ss_family == AF_INET6) {
ipv6 = (struct sockaddr_in6 *)(sa_source);
port = ntohs(ipv6->sin6_port);
} else {
logit(LOG_DEBUG, 0, "%s: Unsupported address family", __func__);
return 1;
}
/*
* we could check that the source is the server we expect, but
* Denys Vlasenko recommends against it: multihomed hosts get it
* wrong too often.
*/
if (NTP_PORT != port) {
logit(LOG_INFO, 0, "%s: invalid port: %u", __func__, port);
return 1;
}
return 0;
}
static double ntpdiff(struct ntptime *start, struct ntptime *stop)
{
int a;
unsigned int b;
a = stop->coarse - start->coarse;
if (stop->fine >= start->fine) {
b = stop->fine - start->fine;
} else {
b = start->fine - stop->fine;
b = ~b;
a -= 1;
}
return a * 1.e6 + b * (1.e6 / 4294967296.0);
}
/* Does more than print, so this name is bogus.
* It also makes time adjustments, both sudden (-s)
* and phase-locking (-l).
* sets *error to the number of microseconds uncertainty in answer
* returns 0 normally, 1 if the message fails sanity checks
*/
static int rfc1305print(uint32_t *data, struct ntptime *arrival, struct ntp_control *ntpc, int *error)
{
/* straight out of RFC-1305 Appendix A */
int li, vn, mode, stratum, prec;
int delay, disp;
#ifdef ENABLE_DEBUG
int poll, refid;
struct ntptime reftime;
#endif
struct ntptime orgtime, rectime, xmttime;
double el_time, st_time, skew1, skew2;
int freq;
const char *drop_reason = NULL;
#define Data(i) ntohl(((uint32_t *)data)[i])
li = Data(0) >> 30 & 0x03;
vn = Data(0) >> 27 & 0x07;
mode = Data(0) >> 24 & 0x07;
stratum = Data(0) >> 16 & 0xff;
#ifdef ENABLE_DEBUG
poll = Data(0) >> 8 & 0xff;
#endif
prec = Data(0) & 0xff;
if (prec & 0x80)
prec |= 0xffffff00;
delay = Data(1);
disp = Data(2);
#ifdef ENABLE_DEBUG
refid = Data(3);
reftime.coarse = Data(4);
reftime.fine = Data(5);
#endif
orgtime.coarse = Data(6);
orgtime.fine = Data(7);
rectime.coarse = Data(8);
rectime.fine = Data(9);
xmttime.coarse = Data(10);
xmttime.fine = Data(11);
#undef Data
#ifdef ENABLE_DEBUG
if (debug) {
logit(LOG_DEBUG, 0, "LI=%d VN=%d Mode=%d Stratum=%d Poll=%d Precision=%d", li, vn, mode, stratum, poll, prec);
logit(LOG_DEBUG, 0, "Delay=%.1f Dispersion=%.1f Refid=%u.%u.%u.%u", sec2u(delay), sec2u(disp),
refid >> 24 & 0xff, refid >> 16 & 0xff, refid >> 8 & 0xff, refid & 0xff);
logit(LOG_DEBUG, 0, "Reference %u.%.6u", reftime.coarse, USEC(reftime.fine));
logit(LOG_DEBUG, 0, "(sent) %u.%.6u", ntpc->time_of_send[0], USEC(ntpc->time_of_send[1]));
logit(LOG_DEBUG, 0, "Originate %u.%.6u", orgtime.coarse, USEC(orgtime.fine));
logit(LOG_DEBUG, 0, "Receive %u.%.6u", rectime.coarse, USEC(rectime.fine));
logit(LOG_DEBUG, 0, "Transmit %u.%.6u", xmttime.coarse, USEC(xmttime.fine));
logit(LOG_DEBUG, 0, "Our recv %u.%.6u", arrival->coarse, USEC(arrival->fine));
}
#endif
el_time = ntpdiff(&orgtime, arrival); /* elapsed */
st_time = ntpdiff(&rectime, &xmttime); /* stall */
skew1 = ntpdiff(&orgtime, &rectime);
skew2 = ntpdiff(&xmttime, arrival);
freq = get_current_freq();
#ifdef ENABLE_DEBUG
if (debug) {
logit(LOG_DEBUG, 0, "Total elapsed: %9.2f", el_time);
logit(LOG_DEBUG, 0, "Server stall: %9.2f", st_time);
logit(LOG_DEBUG, 0, "Slop: %9.2f", el_time - st_time);
logit(LOG_DEBUG, 0, "Skew: %9.2f", (skew1 - skew2) / 2);
logit(LOG_DEBUG, 0, "Frequency: %9d", freq);
logit(LOG_DEBUG, 0, " Day Second Elapsed Stall Skew Dispersion Freq");
}
#endif
/* error checking, see RFC-4330 section 5 */
#define FAIL(x) do { drop_reason=(x); goto fail;} while (0)
if (ntpc->cross_check) {
if (li == 3)
FAIL("LI==3"); /* unsynchronized */
if (vn < 3)
FAIL("VN<3"); /* RFC-4330 documents SNTP v4, but we interoperate with NTP v3 */
if (mode != 4)
FAIL("MODE!=3");
if (orgtime.coarse != ntpc->time_of_send[0] || orgtime.fine != ntpc->time_of_send[1])
FAIL("ORG!=sent");
if (xmttime.coarse == 0 && xmttime.fine == 0)
FAIL("XMT==0");
if (delay > 65536 || delay < -65536)
FAIL("abs(DELAY)>65536");
if (disp > 65536 || disp < -65536)
FAIL("abs(DISP)>65536");
if (stratum == 0)
FAIL("STRATUM==0"); /* kiss o' death */
#undef FAIL
}
/* XXX should I do this if debug flag is set? */
if (ntpc->set_clock) { /* you'd better be root, or ntpclient will exit here! */
set_time(&xmttime);
if (verbose) {
logit(LOG_NOTICE, 0, "Time synchronized to server %s, stratum %d", ntpc->server, stratum);
}
}
/* Not the ideal order for printing, but we want to be sure
* to do all the time-sensitive thinking (and time setting)
* before we start the output, especially fflush() (which
* could be slow). Of course, if debug is turned on, speed
* has gone down the drain anyway. */
if (ntpc->live) {
int new_freq;
new_freq = contemplate_data(arrival->coarse, (skew1 - skew2) / 2, el_time + sec2u(disp), freq);
if (!debug && new_freq != freq)
set_freq(new_freq);
}
/* Display by default for regular users, root users need to supply -d. */
if (debug || ntpc->usermode) {
logit(LOG_NOTICE, 0, "%d %.5d.%.3d %8.1f %8.1f %8.1f %8.1f %9d",
arrival->coarse / 86400, arrival->coarse % 86400,
arrival->fine / 4294967, el_time, st_time,
(skew1 - skew2) / 2, sec2u(disp), freq);
}
*error = el_time - st_time;
return 0;
fail:
if (debug || verbose) {
logit(LOG_ERR, 0, "%d %.5d.%.3d rejected packet: %s",
arrival->coarse / 86400, arrival->coarse % 86400,
arrival->fine / 4294967, drop_reason);
}
return 1;
}
static void setup_receive(int usd, sa_family_t sin_family, uint16_t port)
{
struct sockaddr_in6 sin6;
struct sockaddr_in sin;
struct sockaddr *sa;
socklen_t len;
if (sin_family == AF_INET) {
/* IPV4 */
memset(&sin, 0, sizeof(sin));
sin.sin_family = AF_INET;
sin.sin_addr.s_addr = htonl(INADDR_ANY);
sin.sin_port = htons(port);
sa = (struct sockaddr *)&sin;
len = sizeof(sin);
} else {
/* IPV6 */
memset(&sin6, 0, sizeof(struct sockaddr_in6));
sin6.sin6_family = AF_INET6;
sin6.sin6_port = htons(port);
sin6.sin6_addr = in6addr_any;
sa = (struct sockaddr *)&sin6;
len = sizeof(sin6);
}
if (bind(usd, sa, len) == -1) {
logit(LOG_ERR, errno, "Failed binding to UDP port %u", port);
exit(1);
}
/* listen(usd,3); this isn't TCP; thanks Alexander! */
}
static void setup_transmit(int usd, struct sockaddr_storage *ssp , uint16_t port, struct ntp_control *ntpc)
{
struct sockaddr_in6 *ipv6;
struct sockaddr_in *ipv4;
socklen_t len = 0;
/* Prefer IPv4 over IPv6, for now */
if (ssp->ss_family == AF_INET) {
ipv4 = (struct sockaddr_in *)ssp;
ipv4->sin_port = htons(port);
len = sizeof(struct sockaddr_in);
} else if (ssp->ss_family == AF_INET6) {
ipv6 = (struct sockaddr_in6 *)ssp;
ipv6->sin6_port = htons(port);
len = sizeof(struct sockaddr_in6);
} else {
logit(LOG_ERR, 0, "%s: Unsupported address family", __func__);
exit(1);
}
while (connect(usd, (struct sockaddr *)ssp, len) == -1) {
if (ntpc->live) {
/* Wait here a while, networking is probably not up yet. */
sleep(1);
continue;
}
logit(LOG_ERR, errno, "Failed connecting to NTP server");
exit(1);
}
}
static int setup_socket(struct ntp_control *ntpc)
{
int sd;
struct sockaddr_storage ss;
while (getaddrbyname(ntpc->server, &ss)) {
if (EINVAL != errno && ntpc->live) {
/* Wait here a while, networking is probably not up yet. */
sleep(1);
continue;
}
if (verbose)
logit(LOG_ERR, 0, "Unable lookup %s", ntpc->server);
exit(1);
}
/* open socket based on the server address family */
if (ss.ss_family == AF_INET || ss.ss_family == AF_INET6) {
sd = socket(ss.ss_family, SOCK_DGRAM, IPPROTO_UDP);
} else {
logit(LOG_ERR, 0, "%s: Unsupported address family", __func__);
exit(1);
}
if (sd == -1) {
return -1;
}
setup_receive(sd, ss.ss_family, ntpc->local_udp_port);
setup_transmit(sd, &ss, NTP_PORT, ntpc);
/*
* Every day: reopen socket and perform a new DNS lookup.
*/
alarm(60 * 60 * 24);
return sd;
}
/*
* Signal handler. Take note of the fact that the signal arrived
* so that the main loop can take care of it.
*/
static void handler(int sig)
{
switch (sig) {
case SIGHUP:
case SIGALRM:
/* Trigger NTP sync */
sighup = 1;
break;
case SIGINT:
case SIGQUIT:
case SIGTERM:
case SIGUSR1:
case SIGUSR2:
sigterm = 1;
break;
}
}
static void setup_signals(void)
{
struct sigaction sa;
sa.sa_handler = handler;
sa.sa_flags = 0; /* Interrupt system calls */
sigemptyset(&sa.sa_mask);
sigaction(SIGHUP, &sa, NULL);
sigaction(SIGINT, &sa, NULL);
sigaction(SIGQUIT, &sa, NULL);
sigaction(SIGTERM, &sa, NULL);
sigaction(SIGUSR1, &sa, NULL);
sigaction(SIGUSR2, &sa, NULL);
sigaction(SIGALRM, &sa, NULL);
}
static void primary_loop(int usd, struct ntp_control *ntpc)
{
fd_set fds;
struct sockaddr_storage sa_xmit;
int i, pack_len, probes_sent, error;
socklen_t sa_xmit_len;
struct timeval to;
struct ntptime udp_arrival_ntp;
static uint32_t incoming_word[325];
#define incoming ((char *) incoming_word)
#define sizeof_incoming (sizeof incoming_word)
#ifdef ENABLE_DEBUG
if (debug)
logit(LOG_DEBUG, 0, "Listening...");
#endif
probes_sent = 0;
sa_xmit_len = sizeof(sa_xmit);
to.tv_sec = 0;
to.tv_usec = 0;
while (1) {
if (sigterm) {
ntpc->live = 0;
break;
}
if (sighup) {
sighup = 0;
to.tv_sec = 0;
to.tv_usec = 0;
close(usd);
usd = setup_socket(ntpc);
if (-1 == usd) {
logit(LOG_ERR, errno, "Failed reopening NTP socket");
return;
}
logit(LOG_DEBUG, 0, "Got SIGHUP, triggering resync with NTP server.");
}
FD_ZERO(&fds);
FD_SET(usd, &fds);
i = select(usd + 1, &fds, NULL, NULL, &to); /* Wait on read or error */
if ((i != 1) || (!FD_ISSET(usd, &fds))) {
if (i < 0) {
if (errno != EINTR)
logit(LOG_ERR, errno, "Failed select()");
continue;
}
if (to.tv_sec == 0) {
if (probes_sent >= ntpc->probe_count && ntpc->probe_count != 0)
break;
send_packet(usd, ntpc->time_of_send);
++probes_sent;
to.tv_sec = ntpc->cycle_time;
to.tv_usec = 0;
}
continue;
}
error = ntpc->goodness;
pack_len = recvfrom(usd, incoming, sizeof_incoming, 0, (struct sockaddr *)&sa_xmit, &sa_xmit_len);
if (pack_len < 0) {
logit(LOG_ERR, errno, "Failed recvfrom()");
} else if (pack_len > 0 && (unsigned)pack_len < sizeof_incoming) {
get_packet_timestamp(usd, &udp_arrival_ntp);
if (check_source(pack_len, &sa_xmit, ntpc))
continue;
if (rfc1305print(incoming_word, &udp_arrival_ntp, ntpc, &error) != 0)
continue;
} else {
logit(LOG_ERR, 0, "Ooops. pack_len=%d", pack_len);
}
/*
* best rollover option: specify -g, -s, and -l.
* simpler rollover option: specify -s and -l, which
* triggers a magic -c 1
*/
if ((error < ntpc->goodness && ntpc->goodness != 0) ||
(probes_sent >= ntpc->probe_count && ntpc->probe_count != 0)) {
ntpc->set_clock = 0;
if (!ntpc->live)
break;
}
}
#undef incoming
#undef sizeof_incoming
}
#ifdef ENABLE_REPLAY
static int do_replay(void)
{
char line[100];
int n, day, freq, absolute;
float sec, el_time, st_time, disp;
double skew, errorbar;
int simulated_freq = 0;
unsigned int last_fake_time = 0;
double fake_delta_time = 0.0;
while (fgets(line, sizeof line, stdin)) {
n = sscanf(line, "%d %f %f %f %lf %f %d", &day, &sec, &el_time, &st_time, &skew, &disp, &freq);
if (n == 7) {
logit(LOG_DEBUG, 0, "%s", line);
absolute = day * 86400 + (int)sec;
errorbar = el_time + disp;
#ifdef ENABLE_DEBUG
if (debug)
logit(LOG_DEBUG, 0, "Contemplate %u %.1f %.1f %d", absolute, skew, errorbar, freq);
#endif
if (last_fake_time == 0)
simulated_freq = freq;
fake_delta_time += (absolute - last_fake_time) * ((double)(freq - simulated_freq)) / 65536;
#ifdef ENABLE_DEBUG
if (debug)
logit(LOG_DEBUG, 0, "Fake %f %d", fake_delta_time, simulated_freq);
#endif
skew += fake_delta_time;
freq = simulated_freq;
last_fake_time = absolute;
simulated_freq = contemplate_data(absolute, skew, errorbar, freq);
} else {
logit(LOG_ERR, 0, "Replay input error");
return 2;
}
}
return 0;
}
#endif
static int usage(int code)
{
fprintf(stderr,
"Usage: %s [-dlnstv] [-c count] [-f frequency] [-g goodness]\n"
" [-i interval] [-p port] [-q min_delay]"
#ifdef ENABLE_REPLAY
" [-r]"
#endif
#ifdef ENABLE_SYSLOG
" [-L]"
#endif
" [SERVER]\n", prognm);
fprintf(stderr, "Options:\n"
" -c count Stop after count time measurements. Default: 0 (forever)\n"
" -d Debug, or diagnostics mode Possible to enable more at compile\n"
" -f frequency Initialize frequency offset. Linux only, requires root\n"
" -g goodness Stop after getting a result more accurate than goodness msec,\n"
" microseconds. Default: 0 (forever)\n"
" -h Show summary of command line options and exit\n"
" -i interval Check time every interval seconds. Default: 600\n"
" -l Attempt to lock local clock to server using adjtimex(2)\n"
#ifdef ENABLE_SYSLOG
" -L Use syslog instead of stdout for log messages, enabled\n"
" by default when started as root\n"
#endif
" -n Don't fork. Prevents %s from daemonizing by default\n"
" Only when running as root, does nothing for regular users\n"
" Use -L with this to use syslog as well, for Finit + systemd\n"
" -p port NTP client UDP port. Default: 0 (\"any available\")\n"
" -q min_delay Minimum packet delay for transaction (default 800 microseconds)\n"
#ifdef ENABLE_REPLAY
" -r Replay analysis code based on stdin\n"
#endif
" -s Simple clock set, implies -c 1 unless -l is also set\n"
" -t Trust network and server, no RFC-4330 recommended validation\n"
" -v Be verbose. This option will cause time sync events, hostname\n"
" lookup errors and program version to be displayed\n"
" -V Display version and copyright information\n"
"\n"
"Arguments:\n"
" SERVER Optional NTP server to sync with, default: pool.ntp.org\n"
"\n"
#ifdef PACKAGE_BUGREPORT
"Bug report address: " PACKAGE_BUGREPORT "\n"
#endif
"Project homepage: " PACKAGE_URL "\n", prognm);
return code;
}
static int version(void)
{
fprintf(stderr, "Larry Doolittle's ntpclient v" PACKAGE_VERSION "\n\n");
fprintf(stderr, "Copyright (C) 1997-2015 Larry Doolittle <larry@doolittle.boa.org>\n"
"Copyright (C) 2010-2018 Joachim Nilsson <troglobit@gmail.com>\n\n");
fprintf(stderr, "License GPLv2: GNU GPL version 2 <http://gnu.org/licenses/gpl2.html>\n"
"This is free software: you are free to change and redistribute it.\n"
"There is NO WARRANTY, to the extent permitted by law.\n");
return 1;
}
static const char *progname(const char *arg0)
{
const char *nm;
nm = strrchr(arg0, '/');
if (nm)
nm++;
else
nm = arg0;
return nm;
}
int main(int argc, char *argv[])
{
int c, usd; /* socket */
/* These parameters are settable from the command line
the initializations here provide default behavior */
int daemonize = 0;
int initial_freq = 0; /* initial freq value to use */
struct ntp_control ntpc;
/* Setup application defaults depending on root/user mode */
memset(&ntpc, 0, sizeof(ntpc));
ntpc.probe_count = 0; /* default of 0 means loop forever */
ntpc.cycle_time = 600; /* seconds */
ntpc.goodness = 0;
ntpc.set_clock = 0;
if (geteuid() == 0) {
daemonize = 1;
log_enable++;
ntpc.usermode = 0;
ntpc.live = 1;
ntpc.cross_check = 0;
} else {
ntpc.usermode = 1;
ntpc.live = 0;
ntpc.cross_check = 1;
}
prognm = progname(argv[0]);
while (1) {
char opts[] = "c:df:g:h::i:lnp:q:" REPLAY_OPTION "st" LOG_OPTION "vV?";
c = getopt(argc, argv, opts);
if (c == EOF)
break;
switch (c) {
case 'c':
ntpc.probe_count = atoi(optarg);
break;
case 'd':
debug++;
log_level = LOG_DEBUG;
break;
case 'f':
initial_freq = atoi(optarg);
break;
case 'g':
ntpc.goodness = atoi(optarg);
break;
case 'h':
if (!optarg)
return usage(0);
ntpc.server = optarg;
break;
case 'i':
ntpc.cycle_time = atoi(optarg);
break;
case 'l':
ntpc.live++;
break;
case 'n':
daemonize = 0;
log_enable--;
break;
case 'p':
ntpc.local_udp_port = atoi(optarg);
break;
case 'q':
min_delay = atof(optarg);
break;
#ifdef ENABLE_REPLAY
case 'r':
return do_replay();
#endif
case 's':
ntpc.set_clock++;
break;
case 't':
ntpc.cross_check = 0;
break;
#ifdef ENABLE_SYSLOG
case 'L':
log_enable++;
break;
#endif
case 'v':
++verbose;
break;
case 'V':
return version();
case '?':
default:
return usage(0);
}
}
#ifdef ENABLE_SYSLOG
openlog(prognm, LOG_OPTS, LOG_FACILITY);
setlogmask(LOG_UPTO(log_level));
#endif
if (initial_freq) {
#ifdef ENABLE_DEBUG
logit(LOG_DEBUG, 0, "Initial frequency %d", initial_freq);
#endif
set_freq(initial_freq);
}
if (optind < argc && ntpc.server == NULL)
ntpc.server = argv[optind];
if (ntpc.server == NULL) {
ntpc.server = (char *)"pool.ntp.org";
logit(LOG_DEBUG, 0, "Using server %s", ntpc.server);
}
if (ntpc.set_clock && !ntpc.live && !ntpc.goodness && !ntpc.probe_count)
ntpc.probe_count = 1;
/* If user gives a probe count, then assume non-live run and verbose reporting. */
if (ntpc.probe_count > 0) {
ntpc.live = 0;
verbose = 1;
}
/* respect only applicable MUST of RFC-4330 */
if (ntpc.probe_count != 1 && ntpc.cycle_time < MIN_INTERVAL)
ntpc.cycle_time = MIN_INTERVAL;
#ifdef ENABLE_DEBUG
if (debug) {