OpenBSD-4.6/usr.sbin/ntpd/ntpd.c
/* $OpenBSD: ntpd.c,v 1.66 2009/06/06 18:14:25 pyr Exp $ */
/*
* Copyright (c) 2003, 2004 Henning Brauer <henning@openbsd.org>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF MIND, USE, DATA OR PROFITS, WHETHER
* IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
* OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/wait.h>
#include <netinet/in.h>
#include <errno.h>
#include <poll.h>
#include <pwd.h>
#include <resolv.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <err.h>
#include "ntpd.h"
void sighdlr(int);
__dead void usage(void);
int main(int, char *[]);
int check_child(pid_t, const char *);
int dispatch_imsg(struct ntpd_conf *);
void reset_adjtime(void);
int ntpd_adjtime(double);
void ntpd_adjfreq(double, int);
void ntpd_settime(double);
void readfreq(void);
int writefreq(double);
volatile sig_atomic_t quit = 0;
volatile sig_atomic_t reconfig = 0;
volatile sig_atomic_t sigchld = 0;
struct imsgbuf *ibuf;
int debugsyslog = 0;
int timeout = INFTIM;
void
sighdlr(int sig)
{
switch (sig) {
case SIGTERM:
case SIGINT:
quit = 1;
break;
case SIGCHLD:
sigchld = 1;
break;
case SIGHUP:
reconfig = 1;
break;
}
}
__dead void
usage(void)
{
extern char *__progname;
fprintf(stderr, "usage: %s [-dnSsv] [-f file]\n", __progname);
exit(1);
}
#define POLL_MAX 8
#define PFD_PIPE 0
int
main(int argc, char *argv[])
{
struct ntpd_conf lconf;
struct pollfd pfd[POLL_MAX];
pid_t chld_pid = 0, pid;
const char *conffile;
int ch, nfds;
int pipe_chld[2];
struct passwd *pw;
conffile = CONFFILE;
bzero(&lconf, sizeof(lconf));
log_init(1); /* log to stderr until daemonized */
res_init(); /* XXX */
while ((ch = getopt(argc, argv, "df:nsSv")) != -1) {
switch (ch) {
case 'd':
lconf.debug = 1;
break;
case 'f':
conffile = optarg;
break;
case 'n':
lconf.noaction = 1;
break;
case 's':
lconf.settime = 1;
break;
case 'S':
lconf.settime = 0;
break;
case 'v':
debugsyslog = 1;
break;
default:
usage();
/* NOTREACHED */
}
}
argc -= optind;
argv += optind;
if (argc > 0)
usage();
if (parse_config(conffile, &lconf))
exit(1);
if (lconf.noaction) {
fprintf(stderr, "configuration OK\n");
exit(0);
}
if (geteuid())
errx(1, "need root privileges");
if ((pw = getpwnam(NTPD_USER)) == NULL)
errx(1, "unknown user %s", NTPD_USER);
reset_adjtime();
if (!lconf.settime) {
log_init(lconf.debug);
if (!lconf.debug)
if (daemon(1, 0))
fatal("daemon");
} else
timeout = SETTIME_TIMEOUT * 1000;
if (socketpair(AF_UNIX, SOCK_STREAM, PF_UNSPEC, pipe_chld) == -1)
fatal("socketpair");
signal(SIGCHLD, sighdlr);
/* fork child process */
chld_pid = ntp_main(pipe_chld, &lconf, pw);
setproctitle("[priv]");
readfreq();
signal(SIGTERM, sighdlr);
signal(SIGINT, sighdlr);
signal(SIGHUP, sighdlr);
close(pipe_chld[1]);
if ((ibuf = malloc(sizeof(struct imsgbuf))) == NULL)
fatal(NULL);
imsg_init(ibuf, pipe_chld[0]);
while (quit == 0) {
pfd[PFD_PIPE].fd = ibuf->fd;
pfd[PFD_PIPE].events = POLLIN;
if (ibuf->w.queued)
pfd[PFD_PIPE].events |= POLLOUT;
if ((nfds = poll(pfd, 1, timeout)) == -1)
if (errno != EINTR) {
log_warn("poll error");
quit = 1;
}
if (nfds == 0 && lconf.settime) {
lconf.settime = 0;
timeout = INFTIM;
log_init(lconf.debug);
log_debug("no reply received in time, skipping initial "
"time setting");
if (!lconf.debug)
if (daemon(1, 0))
fatal("daemon");
}
if (nfds > 0 && (pfd[PFD_PIPE].revents & POLLOUT))
if (msgbuf_write(&ibuf->w) < 0) {
log_warn("pipe write error (to child)");
quit = 1;
}
if (nfds > 0 && pfd[PFD_PIPE].revents & POLLIN) {
nfds--;
if (dispatch_imsg(&lconf) == -1)
quit = 1;
}
if (sigchld) {
if (check_child(chld_pid, "child")) {
quit = 1;
chld_pid = 0;
}
sigchld = 0;
}
}
signal(SIGCHLD, SIG_DFL);
if (chld_pid)
kill(chld_pid, SIGTERM);
do {
if ((pid = wait(NULL)) == -1 &&
errno != EINTR && errno != ECHILD)
fatal("wait");
} while (pid != -1 || (pid == -1 && errno == EINTR));
msgbuf_clear(&ibuf->w);
free(ibuf);
log_info("Terminating");
return (0);
}
int
check_child(pid_t pid, const char *pname)
{
int status, sig;
char *signame;
if (waitpid(pid, &status, WNOHANG) > 0) {
if (WIFEXITED(status)) {
log_warnx("Lost child: %s exited", pname);
return (1);
}
if (WIFSIGNALED(status)) {
sig = WTERMSIG(status);
signame = strsignal(sig) ? strsignal(sig) : "unknown";
log_warnx("Lost child: %s terminated; signal %d (%s)",
pname, sig, signame);
return (1);
}
}
return (0);
}
int
dispatch_imsg(struct ntpd_conf *lconf)
{
struct imsg imsg;
int n, cnt;
double d;
char *name;
struct ntp_addr *h, *hn;
struct buf *buf;
if ((n = imsg_read(ibuf)) == -1)
return (-1);
if (n == 0) { /* connection closed */
log_warnx("dispatch_imsg in main: pipe closed");
return (-1);
}
for (;;) {
if ((n = imsg_get(ibuf, &imsg)) == -1)
return (-1);
if (n == 0)
break;
switch (imsg.hdr.type) {
case IMSG_ADJTIME:
if (imsg.hdr.len != IMSG_HEADER_SIZE + sizeof(d))
fatalx("invalid IMSG_ADJTIME received");
memcpy(&d, imsg.data, sizeof(d));
n = ntpd_adjtime(d);
imsg_compose(ibuf, IMSG_ADJTIME, 0, 0, -1,
&n, sizeof(n));
break;
case IMSG_ADJFREQ:
if (imsg.hdr.len != IMSG_HEADER_SIZE + sizeof(d))
fatalx("invalid IMSG_ADJFREQ received");
memcpy(&d, imsg.data, sizeof(d));
ntpd_adjfreq(d, 1);
break;
case IMSG_SETTIME:
if (imsg.hdr.len != IMSG_HEADER_SIZE + sizeof(d))
fatalx("invalid IMSG_SETTIME received");
if (!lconf->settime)
break;
log_init(lconf->debug);
memcpy(&d, imsg.data, sizeof(d));
ntpd_settime(d);
/* daemonize now */
if (!lconf->debug)
if (daemon(1, 0))
fatal("daemon");
lconf->settime = 0;
timeout = INFTIM;
break;
case IMSG_HOST_DNS:
name = imsg.data;
if (imsg.hdr.len < 1 + IMSG_HEADER_SIZE)
fatalx("invalid IMSG_HOST_DNS received");
imsg.hdr.len -= 1 + IMSG_HEADER_SIZE;
if (name[imsg.hdr.len] != '\0' ||
strlen(name) != imsg.hdr.len)
fatalx("invalid IMSG_HOST_DNS received");
if ((cnt = host_dns(name, &hn)) == -1)
break;
buf = imsg_create(ibuf, IMSG_HOST_DNS,
imsg.hdr.peerid, 0,
cnt * sizeof(struct sockaddr_storage));
if (buf == NULL)
break;
if (cnt > 0)
for (h = hn; h != NULL; h = h->next)
imsg_add(buf, &h->ss, sizeof(h->ss));
imsg_close(ibuf, buf);
break;
default:
break;
}
imsg_free(&imsg);
}
return (0);
}
void
reset_adjtime(void)
{
struct timeval tv;
tv.tv_sec = 0;
tv.tv_usec = 0;
if (adjtime(&tv, NULL) == -1)
log_warn("reset adjtime failed");
}
int
ntpd_adjtime(double d)
{
struct timeval tv, olddelta;
int synced = 0;
static int firstadj = 1;
d += getoffset();
if (d >= (double)LOG_NEGLIGIBLE_ADJTIME / 1000 ||
d <= -1 * (double)LOG_NEGLIGIBLE_ADJTIME / 1000)
log_info("adjusting local clock by %fs", d);
else
log_debug("adjusting local clock by %fs", d);
d_to_tv(d, &tv);
if (adjtime(&tv, &olddelta) == -1)
log_warn("adjtime failed");
else if (!firstadj && olddelta.tv_sec == 0 && olddelta.tv_usec == 0)
synced = 1;
firstadj = 0;
return (synced);
}
void
ntpd_adjfreq(double relfreq, int wrlog)
{
int64_t curfreq;
double ppmfreq;
int r;
if (adjfreq(NULL, &curfreq) == -1) {
log_warn("adjfreq failed");
return;
}
/*
* adjfreq's unit is ns/s shifted left 32; convert relfreq to
* that unit before adding. We log values in part per million.
*/
curfreq += relfreq * 1e9 * (1LL << 32);
r = writefreq(curfreq / 1e9 / (1LL << 32));
ppmfreq = relfreq * 1e6;
if (wrlog) {
if (ppmfreq >= LOG_NEGLIGIBLE_ADJFREQ ||
ppmfreq <= -LOG_NEGLIGIBLE_ADJFREQ)
log_info("adjusting clock frequency by %f to %fppm%s",
ppmfreq, curfreq / 1e3 / (1LL << 32),
r ? "" : " (no drift file)");
else
log_debug("adjusting clock frequency by %f to %fppm%s",
ppmfreq, curfreq / 1e3 / (1LL << 32),
r ? "" : " (no drift file)");
}
if (adjfreq(&curfreq, NULL) == -1)
log_warn("adjfreq failed");
}
void
ntpd_settime(double d)
{
struct timeval tv, curtime;
char buf[80];
time_t tval;
if (gettimeofday(&curtime, NULL) == -1) {
log_warn("gettimeofday");
return;
}
d_to_tv(d, &tv);
curtime.tv_usec += tv.tv_usec + 1000000;
curtime.tv_sec += tv.tv_sec - 1 + (curtime.tv_usec / 1000000);
curtime.tv_usec %= 1000000;
if (settimeofday(&curtime, NULL) == -1) {
log_warn("settimeofday");
return;
}
tval = curtime.tv_sec;
strftime(buf, sizeof(buf), "%a %b %e %H:%M:%S %Z %Y",
localtime(&tval));
log_info("set local clock to %s (offset %fs)", buf, d);
}
void
readfreq(void)
{
FILE *fp;
int64_t current;
double d;
fp = fopen(DRIFTFILE, "r");
if (fp == NULL) {
/* if the drift file has been deleted by the user, reset */
current = 0;
if (adjfreq(¤t, NULL) == -1)
log_warn("adjfreq reset failed");
return;
}
/* if we're adjusting frequency already, don't override */
if (adjfreq(NULL, ¤t) == -1)
log_warn("adjfreq failed");
else if (current == 0) {
if (fscanf(fp, "%le", &d) == 1)
ntpd_adjfreq(d, 0);
else
log_warnx("can't read %s", DRIFTFILE);
}
fclose(fp);
}
int
writefreq(double d)
{
int r;
FILE *fp;
static int warnonce = 1;
fp = fopen(DRIFTFILE, "w");
if (fp == NULL) {
if (warnonce) {
log_warn("can't open %s", DRIFTFILE);
warnonce = 0;
}
return 0;
}
fprintf(fp, "%e\n", d);
r = ferror(fp);
if (fclose(fp) != 0 || r != 0) {
if (warnonce) {
log_warnx("can't write %s", DRIFTFILE);
warnonce = 0;
}
unlink(DRIFTFILE);
return 0;
}
return 1;
}