How to figure out if requested OID is in Table with net-snmp API?

Question

I'm working on a solution for Windows SNMP Agent Extension. Simultaneously, I use Net-SNMP for reading and loading OIDs from MIB files. Matching old SNMP objects to Net-SNMP objects is a hard work in C++ and I did it severely. Now lots of problems appears on Set, Get-Next requests for Table objects.

The important thing is how to set OID which refer to table entries or field now.

How can I check if requested OID for Get or Set request is the field or entries of a table in MIB with Net-SNMP API?

Answer 1

Here is some function I prepare for figure out table elements:

If Oid is a field of a table:

BOOL IsInTable(AsnObjectIdentifier pAsnOid) {
    char *          szOidTemp;
    char *          pch;
    oid             root[MAX_OID_LEN];
    size_t          rootlen;

    SnmpMgrOidToStr(&pAsnOid, &szOidTemp);

    memset(root, 0, sizeof(root));
    rootlen = MAX_OID_LEN;
    if (snmp_parse_oid(szOidTemp, root, &rootlen) == NULL) {
        snmp_perror(szOidTemp);
        //exit(1);
        return false;
    }

    struct tree    *tbl = NULL;
    tbl = get_tree(root, rootlen, get_tree_head());

    if (tbl) {
        if (tbl->parent && strstr(strlwr(tbl->parent->label), "entry") > 0) {
            return true;
        }
    }
    return false;
}

If Oid is root of a table:

BOOL IsTableRoot(AsnObjectIdentifier pAsnOid) {
    char *          szOidTemp;
    char *          pch;
    oid             root[MAX_OID_LEN];
    size_t          rootlen;

    SnmpMgrOidToStr(&pAsnOid, &szOidTemp);

    memset(root, 0, sizeof(root));
    rootlen = MAX_OID_LEN;
    if (snmp_parse_oid(szOidTemp, root, &rootlen) == NULL) {
        snmp_perror(szOidTemp);
        //exit(1);
        return false;
    }

    struct tree    *tbl = NULL;
    tbl = get_tree(root, rootlen, get_tree_head());

    if (tbl) {
        if (strstr(strlwr(tbl->label), "table") > 0) {
            return true;
        }
    }
    return false;
}

If Oid is entry or first child of a table:

BOOL IsTableEntry(AsnObjectIdentifier pAsnOid) {
    char *          szOidTemp;
    char *          pch;
    oid             root[MAX_OID_LEN];
    size_t          rootlen;

    SnmpMgrOidToStr(&pAsnOid, &szOidTemp);

    memset(root, 0, sizeof(root));
    rootlen = MAX_OID_LEN;
    if (snmp_parse_oid(szOidTemp, root, &rootlen) == NULL) {
        snmp_perror(szOidTemp);
        //exit(1);
        return false;
    }

    struct tree    *tbl = NULL;
    tbl = get_tree(root, rootlen, get_tree_head());

    if (tbl) {
        if (strstr(strlwr(tbl->label), "entry") > 0) {
            return true;
        }
    }
    return false;
}