net-snmpd timeout on HPUX due to diverging interface data information

Hi net-snmp-coders,

Analyzing why when done to hpux  time snmpwalk -v 1 -c public localhost 1.3.6.1.2.1.25.3.2 always getting timeout, I found that it is due to the way it fetches the mib info using nm library.
For each query for instance
snmpwalk -v 1 -c public localhost 1.3.6.1.2.1.25.3.2.1.3.1035
HOST-RESOURCES-MIB::hrDeviceDescr.1035 = STRING: network interface lan900

It scans the full interface table, but reload the interface table at every calls.
As a consequence
Fetching
1.3.6.1.2.1.25.3.2.1.3.1025  need 3 fetch of the interface table, while 1.3.6.1.2.1.25.3.2.1.3.1079 ( lan944) will fetch it 3 + 5 + 7 +...+ 109 times  so 3024 times


Tests had been made on 5.6.1.1 for compilation facility but the same apply to 5.8

Since the function  Interface_Scan_Next() is always called  to walk the interface table after an Interface_Scan_Init()  which always reset the scanIndex to 0,  I propose to get the count and the if_ptr only when scanIndex is 0 ( or ifptr is 0)
Changes are the same on 5.8 but in the function
Interface_Scan_NextInt() and not Interface_Scan_Next()

int
Interface_Scan_Next(short *Index, char *Name, nmapi_phystat * Retifnet)
{
    static nmapi_phystat *if_ptr = (nmapi_phystat *) 0;
-     int             count = Interface_Scan_Get_Count();
+    static int             count = 0;
    unsigned int    ulen;
    int             ret;
+    int count_prev;

-        if (count) {
-             if_ptr =
-                 (nmapi_phystat *) malloc(sizeof(nmapi_phystat) * count);
-             if (if_ptr == NULL)
-                 return (0);
+    if (!if_ptr || (saveIndex==0)) {
+        count_prev=count;
+        count=Interface_Scan_Get_Count();
+        if (count) {
+            if (!if_ptr){
+                if_ptr =
+                     (nmapi_phystat *) malloc(sizeof(nmapi_phystat) * count);
+            } else if (count != count_prev)    {
+                if_ptr =
+                     (nmapi_phystat *) realloc((void *)if_ptr,sizeof(nmapi_phystat) * count);
+            }
+            if (if_ptr == NULL) {
+                return (0);
+                count = 0;
+            }
+            ulen = (unsigned int) count *sizeof(nmapi_phystat);
+            if ((ret = get_physical_stat(if_ptr, &ulen)) < 0)
+                return (0);             /* EOF */
+
        } else
            return (0);         /* EOF */

    }

    if (saveIndex >= count)
        return (0);             /* EOF */

-     ulen = (unsigned int) count *sizeof(nmapi_phystat);
-     if ((ret = get_physical_stat(if_ptr, &ulen)) < 0)
-          return (0);             /* EOF */

    if (Retifnet)
        *Retifnet = if_ptr[saveIndex];
    if (Name)
        strcpy(Name, if_ptr[saveIndex].nm_device);
    saveIndex++;
    if (Index)
        *Index = saveIndex;
    return (1);                 /* DONE */
}


Best regards,
Laurent Menase

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