Don't rely on the assumption that the size of a READSTAT response is a

multiple of sizeof(ntp_assoc_status_pair).


git-svn-id: https://nagiosplug.svn.sourceforge.net/svnroot/nagiosplug/nagiosplug/trunk@1673 f882894a-f735-0410-b71e-b25c423dba1c

1 files changed, 6 insertions, 5 deletions

diff --git a/plugins/check_ntp.c b/plugins/check_ntp.c
index 99fa9a2..8a08af5 100644
--- a/plugins/check_ntp.c
+++ b/plugins/check_ntp.c
@@ -501,7 +501,7 @@ setup_control_request(ntp_control_message *p, uint8_t opcode, uint16_t seq){
 double jitter_request(const char *host, int *status){
         int conn=-1, i, npeers=0, num_candidates=0, syncsource_found=0;
         int run=0, min_peer_sel=PEER_INCLUDED, num_selected=0, num_valid=0;
-        int peer_offset=0;
+        int peers_size=0, peer_offset=0;
         ntp_assoc_status_pair *peers=NULL;
         ntp_control_message req;
         double rval = 0.0, jitter = -1.0;
@@ -539,11 +539,12 @@ double jitter_request(const char *host, int *status){
                 /* Each peer identifier is 4 bytes in the data section, which
                  * we represent as a ntp_assoc_status_pair datatype.
                  */
-                npeers+=(ntohs(req.count)/sizeof(ntp_assoc_status_pair));
-                if((tmp=realloc(peers, sizeof(ntp_assoc_status_pair)*npeers)) == NULL)
+                peers_size+=ntohs(req.count);
+                if((tmp=realloc(peers, peers_size)) == NULL)
                         free(peers), die(STATE_UNKNOWN, "can not (re)allocate 'peers' buffer\n");
                 peers=tmp;
                 memcpy((void*)((ptrdiff_t)peers+peer_offset), (void*)req.data, ntohs(req.count));
+                npeers=peers_size/sizeof(ntp_assoc_status_pair);
                 peer_offset+=ntohs(req.count);
         } while(req.op&REM_MORE);
 
@@ -596,8 +597,8 @@ double jitter_request(const char *host, int *status){
                                         printf("parsing jitter from peer %.2x: ", ntohs(peers[i].assoc));
                                 }
                                 startofvalue = strchr(req.data, '=');
-                                if(startofvalue != NULL) startofvalue++;
                                 if(startofvalue != NULL) {
+                                        startofvalue++;
                                         jitter = strtod(startofvalue, &nptr);
                                 }
                                 if(startofvalue == NULL || startofvalue==nptr){
@@ -618,7 +619,7 @@ double jitter_request(const char *host, int *status){
         rval = num_valid ? rval / num_valid : -1.0;
 
         close(conn);
-        free(peers);
+        if(peers!=NULL) free(peers);
         /* If we return -1.0, it means no synchronization source was found */
         return rval;
 }