/*
* cleanup_after_child() runs in parent.
*/
static void
cleanup_after_child(
blocking_child * c
)
{
u_int idx;
DEBUG_INSIST(!c->reusable);
free(c->thread_ref);
c->thread_ref = NULL;
c->thread_id = 0;
#ifdef USE_WORK_PIPE
DEBUG_INSIST(-1 != c->resp_read_pipe);
DEBUG_INSIST(-1 != c->resp_write_pipe);
(*addremove_io_fd)(c->resp_read_pipe, c->ispipe, true);
close(c->resp_write_pipe);
close(c->resp_read_pipe);
c->resp_write_pipe = -1;
c->resp_read_pipe = -1;
#else
DEBUG_INSIST(NULL != c->blocking_response_ready);
(*addremove_io_semaphore)(c->blocking_response_ready, true);
#endif
for (idx = 0; idx < c->workitems_alloc; idx++)
c->workitems[idx] = NULL;
c->next_workitem = 0;
c->next_workeritem = 0;
for (idx = 0; idx < c->responses_alloc; idx++)
c->responses[idx] = NULL;
c->next_response = 0;
c->next_workresp = 0;
c->reusable = true;
}
/*
* worker_resp_cb() is invoked when resp_read_pipe is readable.
*/
void
worker_resp_cb(
evutil_socket_t fd,
short what,
void * ctx /* blocking_child * */
)
{
blocking_child * c;
DEBUG_INSIST(EV_READ & what);
c = ctx;
DEBUG_INSIST(fd == c->resp_read_pipe);
process_blocking_resp(c);
}
/* --------------------------------------------------------------------
* Create a worker thread. There are several differences between POSIX
* and Windows, of course -- most notably the Windows thread is no
* detached thread, and we keep the handle around until we want to get
* rid of the thread. The notification scheme also differs: Windows
* makes use of semaphores in both directions, POSIX uses a pipe for
* integration with 'select()' or alike.
*/
static void
start_blocking_thread_internal(
blocking_child * c
)
#ifdef SYS_WINNT
{
BOOL resumed;
c->thread_ref = NULL;
(*addremove_io_semaphore)(c->responses_pending->shnd, FALSE);
c->thr_table[0].thnd =
(HANDLE)_beginthreadex(
NULL,
0,
&blocking_thread,
c,
CREATE_SUSPENDED,
NULL);
if (NULL == c->thr_table[0].thnd) {
msyslog(LOG_ERR, "start blocking thread failed: %m");
exit(-1);
}
/* remember the thread priority is only within the process class */
if (!SetThreadPriority(c->thr_table[0].thnd,
THREAD_PRIORITY_BELOW_NORMAL))
msyslog(LOG_ERR, "Error lowering blocking thread priority: %m");
resumed = ResumeThread(c->thr_table[0].thnd);
DEBUG_INSIST(resumed);
c->thread_ref = &c->thr_table[0];
}
/*
* cleanup_after_child() runs in parent.
*/
static void
cleanup_after_child(
blocking_child * c
)
{
harvest_child_status(c);
if (-1 != c->resp_read_pipe) {
(*addremove_io_fd)(c->resp_read_pipe, c->ispipe, TRUE);
close(c->resp_read_pipe);
c->resp_read_pipe = -1;
}
c->resp_read_ctx = NULL;
DEBUG_INSIST(-1 == c->req_read_pipe);
DEBUG_INSIST(-1 == c->resp_write_pipe);
c->reusable = TRUE;
}
/*
* general fractional timestamp formatting
*
* Many pieces of ntpd require a machine with two's complement
* representation of signed integers, so we don't go through the whole
* rigamarole of creating fully portable code here. But we have to stay
* away from signed integer overflow, as this might cause trouble even
* with two's complement representation.
*/
const char *
format_time_fraction(
time_t secs,
long frac,
int prec
)
{
char * cp;
u_int prec_u;
u_time secs_u;
u_int u;
long fraclimit;
int notneg; /* flag for non-negative value */
ldiv_t qr;
DEBUG_REQUIRE(prec != 0);
LIB_GETBUF(cp);
secs_u = (u_time)secs;
/* check if we need signed or unsigned mode */
notneg = (prec < 0);
prec_u = abs(prec);
/* fraclimit = (long)pow(10, prec_u); */
for (fraclimit = 10, u = 1; u < prec_u; u++) {
DEBUG_INSIST(fraclimit < fraclimit * 10);
fraclimit *= 10;
}
/*
* Since conversion to string uses lots of divisions anyway,
* there's no big extra penalty for normalisation. We do it for
* consistency.
*/
if (frac < 0 || frac >= fraclimit) {
qr = ldiv(frac, fraclimit);
if (qr.rem < 0) {
qr.quot--;
qr.rem += fraclimit;
}
secs_u += (time_t)qr.quot;
frac = qr.rem;
}
/* Get the absolute value of the split representation time. */
notneg = notneg || ((time_t)secs_u >= 0);
if (!notneg) {
secs_u = ~secs_u;
if (0 == frac)
secs_u++;
else
frac = fraclimit - frac;
}
/* finally format the data and return the result */
snprintf(cp, LIB_BUFLENGTH, "%s%" UTIME_FORMAT ".%0*ld",
notneg? "" : "-", secs_u, prec_u, frac);
return cp;
}
static void
start_blocking_thread_internal(
blocking_child * c
)
#ifdef SYS_WINNT
{
thr_ref blocking_child_thread;
u_int blocking_thread_id;
BOOL resumed;
(*addremove_io_semaphore)(c->blocking_response_ready, FALSE);
blocking_child_thread =
(HANDLE)_beginthreadex(
NULL,
0,
&blocking_thread,
c,
CREATE_SUSPENDED,
&blocking_thread_id);
if (NULL == blocking_child_thread) {
msyslog(LOG_ERR, "start blocking thread failed: %m");
exit(-1);
}
c->thread_id = blocking_thread_id;
c->thread_ref = blocking_child_thread;
/* remember the thread priority is only within the process class */
if (!SetThreadPriority(blocking_child_thread,
THREAD_PRIORITY_BELOW_NORMAL))
msyslog(LOG_ERR, "Error lowering blocking thread priority: %m");
resumed = ResumeThread(blocking_child_thread);
DEBUG_INSIST(resumed);
}
/*
* mon_reclaim_entry - Remove an entry from the MRU list and from the
* hash array, then zero-initialize it. Indirectly
* decrements mru_entries.
* The entry is prepared to be reused. Before return, in
* remove_from_hash(), mru_entries is decremented. It is the caller's
* responsibility to increment it again.
*/
static inline void
mon_reclaim_entry(
mon_entry *m
)
{
DEBUG_INSIST(NULL != m);
UNLINK_DLIST(m, mru);
remove_from_hash(m);
ZERO(*m);
}
/* --------------------------------------------------------------------
* Light up a new worker.
*/
static void
start_blocking_thread(
blocking_child * c
)
{
DEBUG_INSIST(!c->reusable);
prepare_child_sems(c);
start_blocking_thread_internal(c);
}
int
send_blocking_req_internal(
blocking_child * c,
blocking_pipe_header * hdr,
void * data
)
{
int octets;
int rc;
DEBUG_REQUIRE(hdr != NULL);
DEBUG_REQUIRE(data != NULL);
DEBUG_REQUIRE(BLOCKING_REQ_MAGIC == hdr->magic_sig);
if (-1 == c->req_write_pipe) {
fork_blocking_child(c);
DEBUG_INSIST(-1 != c->req_write_pipe);
}
octets = sizeof(*hdr);
rc = write(c->req_write_pipe, hdr, octets);
if (rc == octets) {
octets = hdr->octets - sizeof(*hdr);
rc = write(c->req_write_pipe, data, octets);
if (rc == octets)
return 0;
}
if (rc < 0)
msyslog(LOG_ERR,
"send_blocking_req_internal: pipe write: %m");
else
msyslog(LOG_ERR,
"send_blocking_req_internal: short write %d of %d",
rc, octets);
/* Fatal error. Clean up the child process. */
req_child_exit(c);
exit(1); /* otherwise would be return -1 */
}
/*
** xmt_timer_cb
*/
void
xmt_timer_cb(
evutil_socket_t fd,
short what,
void * ctx
)
{
struct timeval start_cb;
struct timeval delay;
xmt_ctx * x;
UNUSED_ARG(fd);
UNUSED_ARG(ctx);
DEBUG_INSIST(EV_TIMEOUT == what);
if (NULL == xmt_q || shutting_down)
return;
gettimeofday_cached(base, &start_cb);
if (xmt_q->sched <= start_cb.tv_sec) {
UNLINK_HEAD_SLIST(x, xmt_q, link);
TRACE(2, ("xmt_timer_cb: at .%6.6u -> %s\n",
(u_int)start_cb.tv_usec, stoa(&x->spkt->addr)));
xmt(x);
free(x);
if (NULL == xmt_q)
return;
}
if (xmt_q->sched <= start_cb.tv_sec) {
event_add(ev_xmt_timer, &gap);
TRACE(2, ("xmt_timer_cb: at .%6.6u gap %6.6u\n",
(u_int)start_cb.tv_usec,
(u_int)gap.tv_usec));
} else {
delay.tv_sec = xmt_q->sched - start_cb.tv_sec;
delay.tv_usec = 0;
event_add(ev_xmt_timer, &delay);
TRACE(2, ("xmt_timer_cb: at .%6.6u next %ld seconds\n",
(u_int)start_cb.tv_usec,
(long)delay.tv_sec));
}
}
/*
* intres_timeout_req(s) is invoked in the parent to schedule an idle
* timeout to fire in s seconds, if not reset earlier by a call to
* intres_timeout_req(0), which clears any pending timeout. When the
* timeout expires, worker_idle_timer_fired() is invoked (again, in the
* parent).
*
* sntp and ntpd each provide implementations adapted to their timers.
*/
void
intres_timeout_req(
u_int seconds /* 0 cancels */
)
{
struct timeval tv_to;
if (NULL == ev_worker_timeout) {
ev_worker_timeout = event_new(base, -1,
EV_TIMEOUT | EV_PERSIST,
&worker_timeout, NULL);
DEBUG_INSIST(NULL != ev_worker_timeout);
} else {
event_del(ev_worker_timeout);
}
if (0 == seconds)
return;
tv_to.tv_sec = seconds;
tv_to.tv_usec = 0;
event_add(ev_worker_timeout, &tv_to);
}
static void
fork_blocking_child(
blocking_child * c
)
{
static int atexit_installed;
static int blocking_pipes[4] = { -1, -1, -1, -1 };
int rc;
int was_pipe;
int is_pipe;
int saved_errno = 0;
int childpid;
int keep_fd;
int fd;
/*
* parent and child communicate via a pair of pipes.
*
* 0 child read request
* 1 parent write request
* 2 parent read response
* 3 child write response
*/
if (-1 == c->req_write_pipe) {
rc = pipe_socketpair(&blocking_pipes[0], &was_pipe);
if (0 != rc) {
saved_errno = errno;
} else {
rc = pipe_socketpair(&blocking_pipes[2], &is_pipe);
if (0 != rc) {
saved_errno = errno;
close(blocking_pipes[0]);
close(blocking_pipes[1]);
} else {
INSIST(was_pipe == is_pipe);
}
}
if (0 != rc) {
errno = saved_errno;
msyslog(LOG_ERR, "unable to create worker pipes: %m");
exit(1);
}
/*
* Move the descriptors the parent will keep open out of the
* low descriptors preferred by C runtime buffered FILE *.
*/
c->req_write_pipe = move_fd(blocking_pipes[1]);
c->resp_read_pipe = move_fd(blocking_pipes[2]);
/*
* wake any worker child on orderly shutdown of the
* daemon so that it can notice the broken pipes and
* go away promptly.
*/
if (!atexit_installed) {
atexit(&send_worker_home_atexit);
atexit_installed = TRUE;
}
}
#ifdef HAVE_DROPROOT
/* defer the fork until after root is dropped */
if (droproot && !root_dropped)
return;
#endif
if (syslog_file != NULL)
fflush(syslog_file);
fflush(stdout);
fflush(stderr);
signal_no_reset(SIGCHLD, SIG_IGN);
childpid = fork();
if (-1 == childpid) {
msyslog(LOG_ERR, "unable to fork worker: %m");
exit(1);
}
if (childpid) {
/* this is the parent */
TRACE(1, ("forked worker child (pid %d)\n", childpid));
c->pid = childpid;
c->ispipe = is_pipe;
/* close the child's pipe descriptors. */
close(blocking_pipes[0]);
close(blocking_pipes[3]);
memset(blocking_pipes, -1, sizeof(blocking_pipes));
/* wire into I/O loop */
(*addremove_io_fd)(c->resp_read_pipe, is_pipe, FALSE);
return; /* parent returns */
}
/*
* The parent gets the child pid as the return value of fork().
* The child must work for it.
*/
c->pid = getpid();
worker_process = TRUE;
/*
* In the child, close all files except stdin, stdout, stderr,
* and the two child ends of the pipes.
*/
DEBUG_INSIST(-1 == c->req_read_pipe);
DEBUG_INSIST(-1 == c->resp_write_pipe);
c->req_read_pipe = blocking_pipes[0];
c->resp_write_pipe = blocking_pipes[3];
kill_asyncio(0);
closelog();
if (syslog_file != NULL) {
fclose(syslog_file);
syslog_file = NULL;
syslogit = TRUE;
}
keep_fd = max(c->req_read_pipe, c->resp_write_pipe);
for (fd = 3; fd < keep_fd; fd++)
if (fd != c->req_read_pipe &&
fd != c->resp_write_pipe)
close(fd);
close_all_beyond(keep_fd);
/*
* We get signals from refclock serial I/O on NetBSD in the
* worker if we do not reset SIGIO's handler to the default.
* It is not conditionalized for NetBSD alone because on
* systems where it is not needed, it is harmless, and that
* allows us to handle unknown others with NetBSD behavior.
* [Bug 1386]
*/
#if defined(USE_SIGIO)
signal_no_reset(SIGIO, SIG_DFL);
#elif defined(USE_SIGPOLL)
signal_no_reset(SIGPOLL, SIG_DFL);
#endif
signal_no_reset(SIGHUP, worker_sighup);
init_logging("ntp_intres", 0, FALSE);
setup_logfile(NULL);
/*
* And now back to the portable code
*/
exit_worker(blocking_child_common(c));
}
/*
* adj_host_clock - Called once every second to update the local clock.
*
* LOCKCLOCK: The only thing this routine does is increment the
* sys_rootdisp variable.
*/
void
adj_host_clock(
void
)
{
double offset_adj;
double freq_adj;
/*
* Update the dispersion since the last update. In contrast to
* NTPv3, NTPv4 does not declare unsynchronized after one day,
* since the dispersion check serves this function. Also,
* since the poll interval can exceed one day, the old test
* would be counterproductive. During the startup clamp period, the
* time constant is clamped at 2.
*/
sys_rootdisp += clock_phi;
#ifndef LOCKCLOCK
if (!ntp_enable || mode_ntpdate)
return;
/*
* Determine the phase adjustment. The gain factor (denominator)
* increases with poll interval, so is dominated by the FLL
* above the Allan intercept. Note the reduced time constant at
* startup.
*/
if (state != EVNT_SYNC) {
offset_adj = 0.;
} else if (freq_cnt > 0) {
offset_adj = clock_offset / (CLOCK_PLL * ULOGTOD(1));
freq_cnt--;
#ifdef KERNEL_PLL
} else if (pll_control && kern_enable) {
offset_adj = 0.;
#endif /* KERNEL_PLL */
} else {
offset_adj = clock_offset / (CLOCK_PLL * ULOGTOD(sys_poll));
}
/*
* If the kernel discipline is enabled the frequency correction
* drift_comp has already been engaged via ntp_adjtime() in
* set_freq(). Otherwise it is a component of the adj_systime()
* offset.
*/
#ifdef KERNEL_PLL
if (pll_control && kern_enable)
freq_adj = 0.;
else
#endif /* KERNEL_PLL */
freq_adj = drift_comp;
/* Bound absolute value of total adjustment to NTP_MAXFREQ. */
if (offset_adj + freq_adj > NTP_MAXFREQ)
offset_adj = NTP_MAXFREQ - freq_adj;
else if (offset_adj + freq_adj < -NTP_MAXFREQ)
offset_adj = -NTP_MAXFREQ - freq_adj;
clock_offset -= offset_adj;
/*
* Windows port adj_systime() must be called each second,
* even if the argument is zero, to ease emulation of
* adjtime() using Windows' slew API which controls the rate
* but does not automatically stop slewing when an offset
* has decayed to zero.
*/
DEBUG_INSIST(enable_panic_check == TRUE);
enable_panic_check = FALSE;
adj_systime(offset_adj + freq_adj);
enable_panic_check = TRUE;
#endif /* LOCKCLOCK */
}
