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authorDenys Vlasenko <vda.linux@googlemail.com>2009-12-02 22:17:45 (GMT)
committer Denys Vlasenko <vda.linux@googlemail.com>2009-12-02 22:17:45 (GMT)
commit907647fb1540cb5303d90f2316dbfe89120db39c (patch)
tree1ec5716345ea491e9e37bc7af448023ad777fdd7
parent4bd51893704e4db5dda0ecca19ebb1f39a574baa (diff)
downloadbusybox-907647fb1540cb5303d90f2316dbfe89120db39c.tar.gz
busybox-907647fb1540cb5303d90f2316dbfe89120db39c.tar.bz2
ntpd: implement -x. shrink code a bit. -69 bytes
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
-rw-r--r--include/usage.h3
-rw-r--r--networking/ntpd.c330
2 files changed, 157 insertions, 176 deletions
diff --git a/include/usage.h b/include/usage.h
index 760e854..6978bb6 100644
--- a/include/usage.h
+++ b/include/usage.h
@@ -3217,9 +3217,8 @@
"\nOptions:" \
"\n -d Verbose" \
"\n -n Do not daemonize" \
- "\n -g Set system time even if offset is > 1000 sec" \
"\n -q Quit after clock is set" \
-/* -N exists for mostly compat reasons, thus Not essential to inform */ \
+/* -N exists for mostly compat reasons, thus not essential to inform */ \
/* the user that it exists: user may use nice as well */ \
/* "\n -N Run at high priority" */ \
"\n -l Run as server on port 123" \
diff --git a/networking/ntpd.c b/networking/ntpd.c
index 320477c..3bca69a 100644
--- a/networking/ntpd.c
+++ b/networking/ntpd.c
@@ -14,11 +14,14 @@
# error "Sorry, your kernel has to support IP_PKTINFO"
#endif
-#define INTERVAL_QUERY_NORMAL 30 /* sync to peers every n secs */
+
+/* Sync to peers every N secs */
+#define INTERVAL_QUERY_NORMAL 30
#define INTERVAL_QUERY_PATHETIC 60
#define INTERVAL_QUERY_AGRESSIVE 5
-#define TRUSTLEVEL_BADPEER 6 /* bad if *less than* TRUSTLEVEL_BADPEER */
+/* Bad if *less than* TRUSTLEVEL_BADPEER */
+#define TRUSTLEVEL_BADPEER 6
#define TRUSTLEVEL_PATHETIC 2
#define TRUSTLEVEL_AGRESSIVE 8
#define TRUSTLEVEL_MAX 10
@@ -26,30 +29,11 @@
#define QSCALE_OFF_MIN 0.05
#define QSCALE_OFF_MAX 0.50
-#define QUERYTIME_MAX 15 /* single query might take n secs max */
-#define OFFSET_ARRAY_SIZE 8
-#define SETTIME_MIN_OFFSET 180 /* min offset for settime at start */
-#define SETTIME_TIMEOUT 15 /* max seconds to wait with -s */
-
-/* Style borrowed from NTP ref/tcpdump and updated for SNTPv4 (RFC2030). */
+/* Single query might take n secs max */
+#define QUERYTIME_MAX 15
+/* Min offset for settime at start. "man ntpd" says it's 128 ms */
+#define STEPTIME_MIN_OFFSET 0.128
-/*
- * RFC Section 3
- *
- * 0 1 2 3
- * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
- * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
- * | Integer Part |
- * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
- * | Fraction Part |
- * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
- *
- * 0 1 2 3
- * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
- * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
- * | Integer Part | Fraction Part |
- * +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
-*/
typedef struct {
uint32_t int_partl;
uint32_t fractionl;
@@ -85,7 +69,7 @@ typedef struct {
enum {
NTP_VERSION = 4,
NTP_MAXSTRATUM = 15,
- /* Leap Second Codes (high order two bits) */
+ /* Leap Second Codes (high order two bits of m_status) */
LI_NOWARNING = (0 << 6), /* no warning */
LI_PLUSSEC = (1 << 6), /* add a second (61 seconds) */
LI_MINUSSEC = (2 << 6), /* minus a second (59 seconds) */
@@ -121,33 +105,28 @@ typedef struct {
uint8_t o_good;
} ntp_offset_t;
+#define OFFSET_ARRAY_SIZE 8
typedef struct {
-//TODO: periodically re-resolve DNS names?
len_and_sockaddr *lsa;
+ char *hostname;
char *dotted;
- double xmttime;
- time_t next;
- time_t deadline;
+ /* When to send new query (if fd == -1)
+ * or when receive times out (if fd >= 0): */
+ time_t next_action_time;
int fd;
- uint8_t state;
uint8_t shift;
uint8_t trustlevel;
ntp_msg_t msg;
+ double xmttime;
ntp_offset_t update;
ntp_offset_t reply[OFFSET_ARRAY_SIZE];
} ntp_peer_t;
-/* for ntp_peer_t::state */
-enum {
- STATE_NONE,
- STATE_QUERY_SENT,
- STATE_REPLY_RECEIVED,
-};
enum {
OPT_n = (1 << 0),
- OPT_g = (1 << 1),
- OPT_q = (1 << 2),
- OPT_N = (1 << 3),
+ OPT_q = (1 << 1),
+ OPT_N = (1 << 2),
+ OPT_x = (1 << 3),
/* Insert new options above this line. */
/* Non-compat options: */
OPT_p = (1 << 4),
@@ -164,12 +143,13 @@ struct globals {
#endif
unsigned verbose;
unsigned peer_cnt;
+ unsigned scale;
uint32_t refid;
uint32_t refid4;
- uint32_t scale;
uint8_t synced;
uint8_t leap;
- int8_t precision;
+#define G_precision -6
+// int8_t precision;
uint8_t stratum;
uint8_t time_is_stepped;
uint8_t first_adj_done;
@@ -183,32 +163,28 @@ static const int const_IPTOS_LOWDELAY = IPTOS_LOWDELAY;
static void
set_next(ntp_peer_t *p, unsigned t)
{
- p->next = time(NULL) + t;
- p->deadline = 0;
+ p->next_action_time = time(NULL) + t;
}
static void
-add_peers(const char *s)
+add_peers(char *s)
{
ntp_peer_t *p;
p = xzalloc(sizeof(*p));
-//TODO: big ntpd uses all IPs, not just 1st, do we need to mimic that?
- p->lsa = xhost2sockaddr(s, 123);
- p->dotted = xmalloc_sockaddr2dotted_noport(&p->lsa->u.sa);
+ p->hostname = s;
+ p->dotted = s;
p->fd = -1;
p->msg.m_status = MODE_CLIENT | (NTP_VERSION << 3);
- if (STATE_NONE != 0)
- p->state = STATE_NONE;
p->trustlevel = TRUSTLEVEL_PATHETIC;
- set_next(p, 0);
+ p->next_action_time = time(NULL); /* = set_next(p, 0); */
llist_add_to(&G.ntp_peers, p);
G.peer_cnt++;
}
static double
-gettime1900fp(void)
+gettime1900d(void)
{
struct timeval tv;
gettimeofday(&tv, NULL); /* never fails */
@@ -268,13 +244,6 @@ d_to_sfp(double d)
}
#endif
-static void
-set_deadline(ntp_peer_t *p, time_t t)
-{
- p->deadline = time(NULL) + t;
- p->next = 0;
-}
-
static unsigned
error_interval(void)
{
@@ -328,8 +297,18 @@ send_query_to_peer(ntp_peer_t *p)
int fd, family;
len_and_sockaddr *local_lsa;
+//TODO: big ntpd uses all IPs, not just 1st, do we need to mimic that?
+//TODO: periodically re-resolve DNS names?
+ if (!p->lsa) {
+ p->lsa = host2sockaddr(p->hostname, 123);
+ if (!p->lsa) {
+ set_next(p, INTERVAL_QUERY_PATHETIC);
+ return -1;
+ }
+ p->dotted = xmalloc_sockaddr2dotted_noport(&p->lsa->u.sa);
+ }
+
family = p->lsa->u.sa.sa_family;
- //was: p->fd = xsocket(family, SOCK_DGRAM, 0);
p->fd = fd = xsocket_type(&local_lsa, family, SOCK_DGRAM);
/* local_lsa has "null" address and port 0 now.
* bind() ensures we have a *particular port* selected by kernel
@@ -362,23 +341,70 @@ send_query_to_peer(ntp_peer_t *p)
p->msg.m_xmttime.int_partl = random();
p->msg.m_xmttime.fractionl = random();
- p->xmttime = gettime1900fp();
+ p->xmttime = gettime1900d();
if (do_sendto(p->fd, /*from:*/ NULL, /*to:*/ &p->lsa->u.sa, /*addrlen:*/ p->lsa->len,
&p->msg, NTP_MSGSIZE_NOAUTH) == -1
) {
+ close(p->fd);
+ p->fd = -1;
set_next(p, INTERVAL_QUERY_PATHETIC);
return -1;
}
if (G.verbose)
bb_error_msg("sent query to %s", p->dotted);
- p->state = STATE_QUERY_SENT;
- set_deadline(p, QUERYTIME_MAX);
+ set_next(p, QUERYTIME_MAX);
return 0;
}
+
+/* Time is stepped only once, when the first packet from a peer is received.
+ */
+static void
+step_time_once(double offset)
+{
+ llist_t *item;
+ struct timeval tv;
+ char buf[80];
+ time_t tval;
+
+ if (G.time_is_stepped)
+ goto bail;
+ G.time_is_stepped = 1;
+
+ /* if the offset is small, don't step, slew (later) */
+ if (offset < STEPTIME_MIN_OFFSET && offset > -STEPTIME_MIN_OFFSET)
+ goto bail;
+
+ gettimeofday(&tv, NULL); /* never fails */
+ offset += tv.tv_sec;
+ offset += 1.0e-6 * tv.tv_usec;
+ d_to_tv(offset, &tv);
+
+ if (settimeofday(&tv, NULL) == -1)
+ bb_perror_msg_and_die("settimeofday");
+
+ tval = tv.tv_sec;
+ strftime(buf, sizeof(buf), "%a %b %e %H:%M:%S %Z %Y", localtime(&tval));
+
+ bb_error_msg("setting clock to %s (offset %fs)", buf, offset);
+
+ for (item = G.ntp_peers; item != NULL; item = item->link) {
+ ntp_peer_t *p = (ntp_peer_t *) item->data;
+ p->next_action_time -= offset;
+ }
+
+ bail:
+ if (option_mask32 & OPT_q)
+ exit(0);
+}
+
+
+/* Time is periodically slewed when we collect enough
+ * good data points.
+ */
static int
compare_offsets(const void *aa, const void *bb)
{
@@ -388,8 +414,7 @@ compare_offsets(const void *aa, const void *bb)
return -1;
return ((*a)->update.o_offset > (*b)->update.o_offset);
}
-
-static uint32_t
+static unsigned
updated_scale(double offset)
{
if (offset < 0)
@@ -400,7 +425,6 @@ updated_scale(double offset)
return QSCALE_OFF_MAX / QSCALE_OFF_MIN;
return QSCALE_OFF_MAX / offset;
}
-
static void
slew_time(void)
{
@@ -409,7 +433,6 @@ slew_time(void)
struct timeval tv;
{
- len_and_sockaddr *lsa;
ntp_peer_t **peers = xzalloc(sizeof(peers[0]) * G.peer_cnt);
unsigned goodpeer_cnt = 0;
unsigned middle;
@@ -418,8 +441,10 @@ slew_time(void)
ntp_peer_t *p = (ntp_peer_t *) item->data;
if (p->trustlevel < TRUSTLEVEL_BADPEER)
continue;
- if (!p->update.o_good)
+ if (!p->update.o_good) {
+ free(peers);
return;
+ }
peers[goodpeer_cnt++] = p;
}
@@ -442,38 +467,38 @@ slew_time(void)
}
G.leap = peers[middle]->update.o_leap;
G.refid4 = peers[middle]->update.o_refid4;
- lsa = peers[middle]->lsa;
G.refid =
#if ENABLE_FEATURE_IPV6
- lsa->u.sa.sa_family != AF_INET ?
+ peers[middle]->lsa->u.sa.sa_family != AF_INET ?
G.refid4 :
#endif
- lsa->u.sin.sin_addr.s_addr;
+ peers[middle]->lsa->u.sin.sin_addr.s_addr;
free(peers);
}
+//TODO: if (offset_median > BIG) step_time(offset_median)?
- bb_error_msg("adjusting clock by %fs, our stratum is %u", offset_median, G.stratum);
+ G.scale = updated_scale(offset_median);
+
+ bb_error_msg("adjusting clock by %fs, our stratum is %u, time scale %u",
+ offset_median, G.stratum, G.scale);
errno = 0;
d_to_tv(offset_median, &tv);
- if (adjtime(&tv, &tv) == -1) {
- bb_perror_msg("adjtime failed"); //TODO: maybe _and_die?
- } else {
- if (G.verbose >= 2)
- bb_error_msg("old adjust: %d.%06u", (int)tv.tv_sec, (unsigned)tv.tv_usec);
- if (G.first_adj_done) {
- uint8_t synced = (tv.tv_sec == 0 && tv.tv_usec == 0);
- if (synced != G.synced) {
- G.synced = synced;
- bb_error_msg("clock is %ssynced", synced ? "" : "un");
- }
+ if (adjtime(&tv, &tv) == -1)
+ bb_perror_msg_and_die("adjtime failed");
+ if (G.verbose >= 2)
+ bb_error_msg("old adjust: %d.%06u", (int)tv.tv_sec, (unsigned)tv.tv_usec);
+
+ if (G.first_adj_done) {
+ uint8_t synced = (tv.tv_sec == 0 && tv.tv_usec == 0);
+ if (synced != G.synced) {
+ G.synced = synced;
+ bb_error_msg("clock is %ssynced", synced ? "" : "un");
}
- G.first_adj_done = 1;
}
+ G.first_adj_done = 1;
- G.reftime = gettime1900fp();
-//TODO: log if G.scale changed?
- G.scale = updated_scale(offset_median);
+ G.reftime = gettime1900d();
clear_good:
for (item = G.ntp_peers; item != NULL; item = item->link) {
@@ -483,52 +508,6 @@ slew_time(void)
}
static void
-step_time_once(double offset)
-{
- ntp_peer_t *p;
- llist_t *item;
- struct timeval tv;
- char buf[80];
- time_t tval;
-
- if (G.time_is_stepped)
- goto bail;
- G.time_is_stepped = 1;
-
- /* if the offset is small, don't call settimeofday */
- if (offset < SETTIME_MIN_OFFSET && offset > -SETTIME_MIN_OFFSET)
- goto bail;
-
- gettimeofday(&tv, NULL); /* never fails */
- offset += tv.tv_sec;
- offset += 1.0e-6 * tv.tv_usec;
- d_to_tv(offset, &tv);
-
- if (settimeofday(&tv, NULL) == -1) {
- bb_perror_msg("settimeofday");
- goto bail;
- }
-
- tval = tv.tv_sec;
- strftime(buf, sizeof(buf), "%a %b %e %H:%M:%S %Z %Y", localtime(&tval));
-
-// Do we want to print message below to system log when daemonized?
- bb_error_msg("setting clock to %s (offset %fs)", buf, offset);
-
- for (item = G.ntp_peers; item != NULL; item = item->link) {
- p = (ntp_peer_t *) item->data;
- if (p->next)
- p->next -= offset;
- if (p->deadline)
- p->deadline -= offset;
- }
-
- bail:
- if (option_mask32 & OPT_q)
- exit(0);
-}
-
-static void
update_peer_data(ntp_peer_t *p)
{
/* Clock filter.
@@ -567,7 +546,6 @@ scale_interval(unsigned requested)
r = (unsigned)random() % (unsigned)(MAX(5, interval / 10));
return (interval + r);
}
-
static void
recv_and_process_peer_pkt(ntp_peer_t *p)
{
@@ -631,7 +609,7 @@ recv_and_process_peer_pkt(ntp_peer_t *p)
* d = (T4 - T1) - (T3 - T2) t = ((T2 - T1) + (T3 - T4)) / 2.
*/
- T4 = gettime1900fp();
+ T4 = gettime1900d();
T1 = p->xmttime;
T2 = lfp_to_d(msg.m_rectime);
T3 = lfp_to_d(msg.m_xmttime);
@@ -668,7 +646,6 @@ recv_and_process_peer_pkt(ntp_peer_t *p)
interval = scale_interval(INTERVAL_QUERY_NORMAL);
set_next(p, interval);
- p->state = STATE_REPLY_RECEIVED;
/* every received reply which we do not discard increases trust */
if (p->trustlevel < TRUSTLEVEL_MAX) {
@@ -690,7 +667,7 @@ recv_and_process_peer_pkt(ntp_peer_t *p)
p->shift = 0;
close_sock:
- /* We do not expect any more packets for now.
+ /* We do not expect any more packets from this peer for now.
* Closing the socket informs kernel about it.
* We open a new socket when we send a new query.
*/
@@ -723,10 +700,10 @@ recv_and_process_client_pkt(void /*int fd*/)
if (size < 0) {
if (errno == EAGAIN)
goto bail;
- bb_perror_msg_and_die("recv_from_to");
+ bb_perror_msg_and_die("recv");
}
addr = xmalloc_sockaddr2dotted_noport(from);
- bb_error_msg("malformed packet received from %s", addr);
+ bb_error_msg("malformed packet received from %s: size %u", addr, (int)size);
free(addr);
goto bail;
}
@@ -743,11 +720,11 @@ recv_and_process_client_pkt(void /*int fd*/)
MODE_SERVER : MODE_SYM_PAS;
msg.m_stratum = G.stratum;
msg.m_ppoll = query_ppoll;
- msg.m_precision = G.precision;
- rectime = gettime1900fp();
+ msg.m_precision = G_precision;
+ rectime = gettime1900d();
msg.m_xmttime = msg.m_rectime = d_to_lfp(rectime);
msg.m_reftime = d_to_lfp(G.reftime);
- //msg.m_xmttime = d_to_lfp(gettime1900fp()); // = msg.m_rectime
+ //msg.m_xmttime = d_to_lfp(gettime1900d()); // = msg.m_rectime
msg.m_orgtime = query_xmttime;
msg.m_rootdelay = d_to_sfp(G.rootdelay);
version = (query_status & VERSION_MASK); /* ... >> VERSION_SHIFT - done below instead */
@@ -859,7 +836,6 @@ static NOINLINE void ntp_init(char **argv)
llist_t *peers;
srandom(getpid());
- /* tzset(); - why? it's called automatically when needed, no? */
if (getuid())
bb_error_msg_and_die(bb_msg_you_must_be_root);
@@ -867,16 +843,15 @@ static NOINLINE void ntp_init(char **argv)
peers = NULL;
opt_complementary = "dd:p::"; /* d: counter, p: list */
opts = getopt32(argv,
- "ngqN" /* compat */
+ "nqNx" /* compat */
"p:"IF_FEATURE_NTPD_SERVER("l") /* NOT compat */
"d" /* compat */
- "46aAbLx", /* compat, ignored */
+ "46aAbgL", /* compat, ignored */
&peers, &G.verbose);
if (!(opts & (OPT_p|OPT_l)))
bb_show_usage();
-//WRONG
-// if (opts & OPT_g)
-// G.time_is_stepped = 1;
+ if (opts & OPT_x) /* disable stepping, only slew is allowed */
+ G.time_is_stepped = 1;
while (peers)
add_peers(llist_pop(&peers));
if (!(opts & OPT_n)) {
@@ -896,23 +871,28 @@ static NOINLINE void ntp_init(char **argv)
setpriority(PRIO_PROCESS, 0, -15);
/* Set some globals */
+#if 0
+ /* With constant b = 100, G.precision is also constant -6.
+ * Uncomment this and you'll see */
{
int prec = 0;
int b;
-#if 0
+# if 0
struct timespec tp;
/* We can use sys_clock_getres but assuming 10ms tick should be fine */
clock_getres(CLOCK_REALTIME, &tp);
tp.tv_sec = 0;
tp.tv_nsec = 10000000;
b = 1000000000 / tp.tv_nsec; /* convert to Hz */
-#else
+# else
b = 100; /* b = 1000000000/10000000 = 100 */
-#endif
+# endif
while (b > 1)
prec--, b >>= 1;
- G.precision = prec;
+ //G.precision = prec;
+ bb_error_msg("G.precision:%d", prec); /* -6 */
}
+#endif
G.scale = 1;
bb_signals((1 << SIGTERM) | (1 << SIGINT), record_signo);
@@ -963,31 +943,33 @@ int ntpd_main(int argc UNUSED_PARAM, char **argv)
for (item = g.ntp_peers; item != NULL; item = item->link) {
ntp_peer_t *p = (ntp_peer_t *) item->data;
- if (p->next != 0 && p->next <= cur_time) {
- /* Time to send new req */
- trial_cnt++;
- if (send_query_to_peer(p) == 0)
- sent_cnt++;
- }
- if (p->deadline != 0 && p->deadline <= cur_time) {
- /* Timed out waiting for reply */
- timeout = error_interval();
- bb_error_msg("timed out waiting for %s, "
- "next query in %us", p->dotted, timeout);
- if (p->trustlevel >= TRUSTLEVEL_BADPEER) {
- p->trustlevel /= 2;
- if (p->trustlevel < TRUSTLEVEL_BADPEER)
- bb_error_msg("peer %s now invalid", p->dotted);
+ /* Overflow-safe "if (p->next_action_time <= cur_time) ..." */
+ if ((int)(cur_time - p->next_action_time) >= 0) {
+ if (p->fd == -1) {
+ /* Time to send new req */
+ trial_cnt++;
+ if (send_query_to_peer(p) == 0)
+ sent_cnt++;
+ } else {
+ /* Timed out waiting for reply */
+ close(p->fd);
+ p->fd = -1;
+ timeout = error_interval();
+ bb_error_msg("timed out waiting for %s, "
+ "next query in %us", p->dotted, timeout);
+ if (p->trustlevel >= TRUSTLEVEL_BADPEER) {
+ p->trustlevel /= 2;
+ if (p->trustlevel < TRUSTLEVEL_BADPEER)
+ bb_error_msg("peer %s now invalid", p->dotted);
+ }
+ set_next(p, timeout);
}
- set_next(p, timeout);
}
- if (p->next != 0 && p->next < nextaction)
- nextaction = p->next;
- if (p->deadline != 0 && p->deadline < nextaction)
- nextaction = p->deadline;
+ if (p->next_action_time < nextaction)
+ nextaction = p->next_action_time;
- if (p->state == STATE_QUERY_SENT) {
+ if (p->fd >= 0) {
/* Wait for reply from this peer */
pfd[i].fd = p->fd;
pfd[i].events = POLLIN;
@@ -1005,7 +987,7 @@ int ntpd_main(int argc UNUSED_PARAM, char **argv)
/* Here we may block */
if (g.verbose >= 2)
- bb_error_msg("poll %u sec, sockets:%u", timeout, i);
+ bb_error_msg("poll %us, sockets:%u", timeout, i);
nfds = poll(pfd, i, timeout * 1000);
if (nfds <= 0)
continue;