I am encountering an issue regarding Net-SNMP version 5.9.4.
I am trying to register my table and scalar into existing oid list, but failed.
Before I continue, I ensured that dlmod is working, and all register handler are running, and my own module code is working correctly in other built, so please take that for granted.

This is how I run my snmpd

snmpd -f -C -c /etc/snmpd/snmpd.conf -Dsubtree,mib_init,mib_load,register_mib,wtest

and here’s my snmpd.conf file

com2sec         rw_sec_name         default         private
com2sec         ro_sec_name         default         public
group   RWGroupLan      v1      rw_sec_name
group   ROGroupLan      v1      ro_sec_name
group   RWGroupLan      v2c     rw_sec_name
group   ROGroupLan      v2c     ro_sec_name
access  RWGroupLan      ""      any     noauth  exact   all     all     none
access  ROGroupLan      ""      any     noauth  exact   all     none    none
view    all     included        .1      80
master agentx
agentxsocket tcp:localhost:701
dlmod netsnmpObjects /lib/libnetsnmpObjects.so

The problem lies when loading netsnmpObjects, when registering handler for the netsnmpObjects table, the snmpd search for context, subtree, and trying to inject oid. When read the config line ” dlmod netsnmpObjects /lib/libnetsnmpObjects.so”, it searchs the context, somehow its NULL, and treat it as a new list. After further research, the problem lies with the global variable “static lookup_cache_context *thecontextcache = NULL;”

Base on the log, when registering mytable

Creating registration name myTable.
trace: netsnmp_inject_handler_before(): agent_handler.c, 453:
handler:inject: injecting table_iterator before myTable
trace: netsnmp_inject_handler_before(): agent_handler.c, 453:
handler:inject: injecting table before table_iterator
trace: netsnmp_register_handler(): agent_handler.c, 276:
handler::register: Registering myTable (::table::table_iterator::myTable) at .1.3.6.1.4.1.1234.12
trace: netsnmp_inject_handler_before(): agent_handler.c, 453:
handler:inject: injecting bulk_to_next before table
trace: netsnmp_register_mib(): agent_registry.c, 1164:
register_mib: registering "myTable" at .1.3.6.1.4.1.1234.12 with context "(null)"
trace: netsnmp_subtree_find_first(): agent_registry.c, 320:
subtree: looking for subtree for context: ""
trace: netsnmp_subtree_find_first(): agent_registry.c, 329:
subtree: didn't find a subtree for context: ""
trace: netsnmp_register_handler(): agent_handler.c, 276:
handler::register: Registering  (::null) at .0

I am building net-snmp-5.9.4 with static library, and compile my mib module as shared object. Is there any way to work around it, or would it help if I build net-snmp-5.9.4 as shared? But I think they will create separate static variable as well.

If there is any insight, please let me know. Thanks.