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

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

diff --git a/networking/ntpd.c b/networking/ntpd.c
index b100caa0904ab425b7579bd73b1d683abf8c0ed5..320477c132c8448f0e97736833aa976550cee85b 100644 (file)
--- a/networking/ntpd.c
+++ b/networking/ntpd.c
@@ -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);