RESOLVED BY implementing make_data_context
iinfo->make_data_context = context_convert_function;
. . .
void * context_convert_function( void *loop_context, netsnmp_iterator_info
*iinfo ) { Context_Data *datactx = SNMP_MALLOC_TYPEDEF(Context_Data);
if (!datactx) return NULL; strncpy( datactx->L1line,
L1.front().c_str(), 1000 ); datactx->len = L1.front().length();
return datactx; }
On Thursday, January 5, 2023 at 02:28:49 p.m. EST, Ian C via Net-snmp-users
<net-snmp-users@lists.sourceforge.net> wrote:
I have a sub-agent which I'm hoping will handle snmpwalk requests. Presently
what is happening is that my get_first_data_point() reads a file (a QNX PPS
object to be specific), each line in the file represents on table row. Each
line is json-formatted and gets parsed to the field level. Reading of the
entire file happens once in get_first_data_point(), each line in that file then
becomes a element within a std::list<std::string>
typedef struct context_data_s {
char L1line[1000];
int len;
} context_data;
std::list<std::string> L1;
void readL1PpsData()
{
... For each line read do a
... L1.push_back( line )
... all fine here
}
netsnmp_variable_list *
inputSourcesInfoTable_get_first_data_point(void **my_loop_context,
void **my_data_context,
netsnmp_variable_list *put_index_data,
netsnmp_iterator_info *mydata)
{
DEBUGMSGTL(("SourcesInfoTable", "1st get_first_data_point() before
populate L1 size %d \n", (int)L1.size()));
context_data * L1ctx = SNMP_MALLOC_TYPEDEF(context_data);
readL1PpsData( L1 );
DEBUGMSGTL(("SourcesInfoTable", "1st get_first_data_point() after
populate L1 size %d \n", (int)L1.size()));
DEBUGMSGTL(("SourcesInfoTable", "1st get_first_data_point() front()
|%s| \n", L1.front().c_str()));
strncpy( L1ctx->L1line, L1.front().c_str(), 1000 );
L1ctx->len = L1.front().length();
L1_set_index_value( put_index_data );
*my_loop_context = L1ctx;
*my_data_context = L1ctx->L1line;
return put_index_data;
}
netsnmp_variable_list *
inputSourcesInfoTable_get_next_data_point(void **my_loop_context,
void **my_data_context,
netsnmp_variable_list *put_index_data,
netsnmp_iterator_info *mydata)
{
DEBUGMSGTL(("SourcesInfoTable", "N_th get_next_data_point() L1 size %d
\n", (int)L1.size()));
if( L1.size() == 0 ) {
/* End of routes. stop here by returning NULL */
//SNMP_FREE(position);
*my_loop_context = NULL;
*my_data_context = NULL;
return NULL;
}
context_data * L1ctx = (context_data*)*my_loop_context;
L1.pop_front();
strncpy( L1ctx->L1line, L1.front().c_str(), 1000 );
L1ctx->len = L1.front().length();
L1_set_index_value( put_index_data );
*my_loop_context = L1ctx;
*my_data_context = L1ctx->L1line;
return put_index_data;
}
The issue that I'm having is that once my handler gets called it only has empty
strings as data_context.
int
inputSourcesInfoTable_handler(
netsnmp_mib_handler *handler,
netsnmp_handler_registration *reginfo,
netsnmp_agent_request_info *reqinfo,
netsnmp_request_info *requests) {
netsnmp_request_info *request;
netsnmp_table_request_info *table_info;
std::string s = L1.front();
DEBUGMSGTL(("SourcesInfoTable", "entering handler() request (%d)\n",
reqinfo->mode ));
switch (reqinfo->mode) {
/*
* Read-support (also covers GetNext requests)
*/
case MODE_GET:
for ( request = requests; request; request = request->next ) {
char *data_context =
(char*)netsnmp_extract_iterator_context( request );
std::string sDbg;
if( data_context == NULL ) {
DEBUGMSGTL(("SourcesInfoTable", " handler()
data_context NULL"));
continue;
}
else {
char dbg[40];
memset( dbg, 0, 40 );
strncpy( dbg, data_context, 39 );
DEBUGMSGTL(("SourcesInfoTable", " handler() dbg is
|%s|\n", dbg)); // <-------- HERE always ||
}
table_info = netsnmp_extract_table_info( request );
switch (table_info->colnum) {
. . . SNIP! . . .
Q: How am I screwing up the data_context?
Q: Is it normal for the handler to only get called once get_next_data_point
returns NULL?
Thanks for the help
Ian
Ps. Note that I've used mib2c.iterate.conf to generate priliminary code and
then modified as per HostsTable & RouteTable examples.
_______________________________________________
Net-snmp-users mailing list
Net-snmp-users@lists.sourceforge.net
Please see the following page to unsubscribe or change other options:
https://lists.sourceforge.net/lists/listinfo/net-snmp-users
_______________________________________________
Net-snmp-users mailing list
Net-snmp-users@lists.sourceforge.net
Please see the following page to unsubscribe or change other options:
https://lists.sourceforge.net/lists/listinfo/net-snmp-users
