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4bd518937

Denys Vlasenko

2009-12-02

FAILED Duration: 30s

Subject

ntpd: fix malloc-too-short bug; code shrink -76 bytes

Binary

No binary (build failed)

Architecture & Compiler Flags

Architecture: x86_64-linux-gnu Compiler: gcc (Ubuntu 11.4.0-1ubuntu1~22.04.3) 11.4.0

—

Build Log

(log yok)

Commit Diff GitHub →

networking/ntpd.c +27 -45

networking/ntpd.c+27 -45

@@ -113,7 +113,7 @@ enum {
	typedef struct {
	double o_offset;
	double o_delay;
-	//UNUSED: double o_error;
+	//UNUSED: double o_error;
	time_t o_rcvd;
	uint32_t o_refid4;
	uint8_t o_leap;
@@ -404,42 +404,34 @@ updated_scale(double offset)
	static void
	slew_time(void)
	{
-	ntp_peer_t *p;
-	llist_t *item;
-	unsigned offset_cnt;
-	double offset_median;
-	struct timeval tv;
-
-	offset_cnt = 0;
-	for (item = G.ntp_peers; item != NULL; item = item->link) {
-	p = (ntp_peer_t *) item->data;
-	if (p->trustlevel < TRUSTLEVEL_BADPEER)
-	continue;
-	if (!p->update.o_good)
-	return;
-	offset_cnt++;
-	}
-
-	if (offset_cnt == 0)
-	goto clear_good;
+	llist_t *item;
+	double offset_median;
+	struct timeval tv;

	{
	len_and_sockaddr *lsa;
+	ntp_peer_t *peers = xzalloc(sizeof(peers[0]) G.peer_cnt);
+	unsigned goodpeer_cnt = 0;
	unsigned middle;
-	unsigned i = 0;
-	ntp_peer_t *peers = xzalloc(sizeof(peers[0]) offset_cnt);

	for (item = G.ntp_peers; item != NULL; item = item->link) {
-	p = (ntp_peer_t *) item->data;
+	ntp_peer_t p = (ntp_peer_t ) item->data;
	if (p->trustlevel < TRUSTLEVEL_BADPEER)
	continue;
-	peers[i++] = p;
+	if (!p->update.o_good)
+	return;
+	peers[goodpeer_cnt++] = p;
+	}
+
+	if (goodpeer_cnt == 0) {
+	free(peers);
+	goto clear_good;
	}

-	qsort(peers, offset_cnt, sizeof(peers[0]), compare_offsets);
+	qsort(peers, goodpeer_cnt, sizeof(peers[0]), compare_offsets);

-	middle = offset_cnt / 2;
-	if (middle != 0 && (offset_cnt & 1) == 0) {
+	middle = goodpeer_cnt / 2;
+	if (middle != 0 && (goodpeer_cnt & 1) == 0) {
	offset_median = (peers[middle-1]->update.o_offset + peers[middle]->update.o_offset) / 2;
	G.rootdelay = (peers[middle-1]->update.o_delay + peers[middle]->update.o_delay) / 2;
	G.stratum = 1 + MAX(peers[middle-1]->update.o_stratum, peers[middle]->update.o_stratum);
@@ -480,11 +472,12 @@ slew_time(void)
	}

	G.reftime = gettime1900fp();
+	//TODO: log if G.scale changed?
	G.scale = updated_scale(offset_median);

	clear_good:
	for (item = G.ntp_peers; item != NULL; item = item->link) {
-	p = (ntp_peer_t *) item->data;
+	ntp_peer_t p = (ntp_peer_t ) item->data;
	p->update.o_good = 0;
	}
	}
@@ -512,7 +505,7 @@ step_time_once(double offset)
	d_to_tv(offset, &tv);

	if (settimeofday(&tv, NULL) == -1) {
-	bb_error_msg("settimeofday");
+	bb_perror_msg("settimeofday");
	goto bail;
	}

@@ -544,22 +537,13 @@ update_peer_data(ntp_peer_t *p)
	* Invalidate it and all older ones.
	*/
	int i;
-	int best = best; /* for compiler */
-	int good;
+	int best = -1;
+	int good = 0;

-	good = 0;
	for (i = 0; i < OFFSET_ARRAY_SIZE; i++) {
	if (p->reply[i].o_good) {
	good++;
-	best = i++;
-	break;
-	}
-	}
-
-	for (; i < OFFSET_ARRAY_SIZE; i++) {
-	if (p->reply[i].o_good) {
-	good++;
-	if (p->reply[i].o_delay < p->reply[best].o_delay)
+	if (best < 0 \|\| p->reply[i].o_delay < p->reply[best].o_delay)
	best = i;
	}
	}
@@ -612,8 +596,6 @@ recv_and_process_peer_pkt(ntp_peer_t *p)
	xfunc_die();
	}

-	T4 = gettime1900fp();
-
	if (size != NTP_MSGSIZE_NOAUTH && size != NTP_MSGSIZE) {
	bb_error_msg("malformed packet received from %s", p->dotted);
	goto bail;
@@ -649,6 +631,7 @@ recv_and_process_peer_pkt(ntp_peer_t *p)
	* d = (T4 - T1) - (T3 - T2) t = ((T2 - T1) + (T3 - T4)) / 2.
	*/

+	T4 = gettime1900fp();
	T1 = p->xmttime;
	T2 = lfp_to_d(msg.m_rectime);
	T3 = lfp_to_d(msg.m_xmttime);
@@ -658,14 +641,13 @@ recv_and_process_peer_pkt(ntp_peer_t *p)
	offset->o_offset = ((T2 - T1) + (T3 - T4)) / 2;
	offset->o_delay = (T4 - T1) - (T3 - T2);
	if (offset->o_delay < 0) {
+	bb_error_msg("reply from %s: negative delay %f", p->dotted, offset->o_delay);
	interval = error_interval();
	set_next(p, interval);
-	bb_error_msg("reply from %s: negative delay %f", p->dotted, p->reply[p->shift].o_delay);
	goto close_sock;
	}
	//UNUSED: offset->o_error = (T2 - T1) - (T3 - T4);
-	// Can we use (T4 - OFFSET_1900_1970) instead of time(NULL)?
-	offset->o_rcvd = time(NULL);
+	offset->o_rcvd = time(NULL); /* can use (time_t)(T4 - OFFSET_1900_1970) too */
	offset->o_good = 1;

	offset->o_leap = (msg.m_status & LI_MASK);