On 28 March 2011 08:29, Manjit <manjit.si...@globaledgesoft.com> wrote: > > How the handlers are registered for a particular oid.
This basically uses 'netsnmp_register_handler()' (either directly, or via another helper registration call, which typically sets up the helper and handler chain information and then calls 'netsnmp_register_handler()') > What data structure net-snmp using to implement this. netsnmp_register_handler() [see agent/agent_handler.c] takes a netsnmp_handler_registration pointer, and calls netsnmp_register_mib() [agent/agent_registry.c] This converts the registration structure information into a netsnmp_subtree structure [defined in <net-snmp/agent/var_struct.h>] These are linked into a list, ordered by OID. The one unusual aspect of this is that each node is actually the head of another *list* of registration entries (via the 'children' field) - all sharing the same OID range - with the most specific registration coming first. > > How the tree is searched whenever a request arrives for a particular oid. The agent searches this list to find the subtree entry that contains the specified OID (i.e. lying within start_a and end_a). It takes this entry (the top one in the list of registrations with the same range), and calls the corresponding handler chain to process the request varbind. (There's actually a lookup cache which speeds up this search, so the code looks rather more complicated than this brief description implies, but that doesn't affect the underlying behaviour) I've skipped over a lot of the detail - but hopefully that's enough to get you started. Dave ------------------------------------------------------------------------------ Enable your software for Intel(R) Active Management Technology to meet the growing manageability and security demands of your customers. Businesses are taking advantage of Intel(R) vPro (TM) technology - will your software be a part of the solution? Download the Intel(R) Manageability Checker today! http://p.sf.net/sfu/intel-dev2devmar _______________________________________________ Net-snmp-coders mailing list Net-snmp-coders@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/net-snmp-coders
