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

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

1 files changed, 27 insertions, 45 deletions

diff --git a/networking/ntpd.c b/networking/ntpd.c
index b100caa09..320477c13 100644
--- 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);