Re: snmp agent crashed when i used the tool snmpwalk running through out my private MIB(a table).

Hi,Dave

I'm really sorry,I changed the name of My table & files,so when you
encounter the
rsfwSysAntivirusTable_handler ,yeah,it equals rsfwTable_handler ,and the
same
as the files.

Also,sorry for my poor english.

forgive me please!
Thanks for your help!


Regards,

Jiang

On 12/22/06, jiang jilin <[email protected]> wrote:
>
> Thanks for your reply,Dave.
>
> Maybe,I should modify the rsfwTable_handler routine shown as follows,
>
>  /** handles requests for the rsfwTable table */
> int
> rsfwTable_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;
>     struct rsfwTable_entry *table_entry;
>
>
>     switch (reqinfo->mode) {
>         /*
>          * Read-support (also covers GetNext requests)
>          */
>        case MODE_GET:
>         for (request = requests; request; request = request->next) {
>             table_entry = (struct rsfwTable_entry *)
>                 netsnmp_extract_iterator_context(request);
>
>             table_info = netsnmp_extract_table_info(request);
>
>
>
>             switch (table_info->colnum) {
>             case COLUMN_RSFWFILES:
>
>                 snmp_set_var_typed_integer(request->requestvb,
> ASN_COUNTER,
>                                            table_entry->
>                                            rsfwFiles);
>                 break;
>             case COLUMN_RSFWFILESINSCAN:
>
>                 snmp_set_var_typed_integer(request->requestvb,
> ASN_COUNTER,
>                                            table_entry->
>                                            rsfwFilesInScan);
>
>                 break;
>             default:
>                 /*
>                  * An unsupported/unreadable column (if applicable)
>                  */
>
>                 snmp_set_var_typed_value(request->requestvb,
>                                          SNMP_NOSUCHOBJECT, NULL, 0);
>             }
>         }
>         break;
>
>     }
>     DEBUGMSGTL(("rising","END ...handler of antivirusTable\n"));
>     return SNMP_ERR_NOERROR;
> }
> you know,I used GDB to debug the agent,and I traced the procedure at
> the routine  rsfwTable_handler.
>
> gdb>bt
> #0  rsfwTable_handler (handler=0x80a1e60, reginfo=0x80a1ea0,
>     reqinfo=0x80e75c8, requests=0x810ebe0) at rfw/rs.c:332
> #1  0xb7e20902 in netsnmp_call_handler (next_handler=0x80a1e60,
>     reginfo=0x80a1ea0, reqinfo=0x80e75c8, requests=0x810ebe0)
>     at agent_handler.c:428
> #2  0xb7e20f33 in netsnmp_call_next_handler (current=0x80a1b38,
>     reginfo=0x80a1ea0, reqinfo=0x80e75c8, requests=0x810ebe0)
>     at agent_handler.c:533
> #3  0xb7dfbf09 in netsnmp_table_iterator_helper_handler
> (handler=0x80a1b38,
>     reginfo=0x80a1ea0, reqinfo=0x80e75c8, requests=0x810ebe0)
>     at table_iterator.c:781
> #4  0xb7e20902 in netsnmp_call_handler (next_handler=0x80a1b38,
>     reginfo=0x80a1ea0, reqinfo=0x80e75c8, requests=0x810ebe0)
>     at agent_handler.c:428
> #5  0xb7e20f33 in netsnmp_call_next_handler (current=0x80a28a0,
>     reginfo=0x80a1ea0, reqinfo=0x80e75c8, requests=0x810ebe0)
>     at agent_handler.c:533
> #6  0xb7e01f3f in table_helper_handler (handler=0x80a28a0,
> reginfo=0x80a1ea0,
>     reqinfo=0x80e75c8, requests=0x810ebe0) at table.c:619
> #7  0xb7e20902 in netsnmp_call_handler (next_handler=0x80a28a0,
>     reginfo=0x80a1ea0, reqinfo=0x80e75c8, requests=0x810ebe0)
>     at agent_handler.c:428
> #8  0xb7e20cf8 in netsnmp_call_handlers (reginfo=0x80a1ea0,
> reqinfo=0x80e75c8,
>     requests=0x810ebe0) at agent_handler.c:509
> #9  0xb7e160f7 in handle_var_requests (asp=0x810e218) at snmp_agent.c:2474
> #10 0xb7e17478 in handle_pdu (asp=0x810e218) at snmp_agent.c:3251
> #11 0xb7e1702d in netsnmp_handle_request (asp=0x810e218,
> status=1927183776)
>
>
> gdb>n
> 0xb7e95d73      358                     break;
> gdb>n
> 335         switch (reqinfo->mode) {
> gdb>n
> 342             for (request = requests; request; request = request->next)
> {
> (gdb)
> 343                 table_entry = (struct rsfwTable_entry *)
> (gdb)
> 347                 table_info = netsnmp_extract_table_info(request);
> (gdb)
> 0xb7e95ce6      358                     break;
>
> (gdb)
> 352                 switch (table_info->colnum) {
> (gdb)
> 361                     snmp_set_var_typed_integer(request->requestvb,
> ASN_COUNTER,
> (gdb)
>
> Program received signal SIGSEGV, Segmentation fault.
> 0xb7e95b20 in rsfwTable_handler (handler=0x80a1e60,
>     reginfo=0x80a1ea0, reqinfo=0x0, requests=0x810ebe0) at rfw/rs.c:361
> 361                     snmp_set_var_typed_integer(request->requestvb,
> ASN_COUNTER,
> so far,we''ve seen that the result the agent  received signal SIGSEGV,and
> again,I found the pointer reqinfo had been NULL(==0) with using GDB.Hereis its output:
>
> Breakpoint 1, rsfwSysAntivirusTable_handler (handler=0x80a1e60,
>     reginfo=0x80a1ea0, reqinfo=0x80e75c8, requests=0x810ebe0) at
> rfw/rising.c:332
> 332         DEBUGMSGTL(("rising","handler of antivirusTable\n"));
> (gdb) n
> 0xb7ed1d73      358                     break;
> (gdb)
> 335         switch (reqinfo->mode) {
> (gdb) p request
> $1 = (netsnmp_request_info *) 0xb7ed1910
> (gdb) p reqinfo
> $2 = (netsnmp_agent_request_info *) 0x0
>
> So,we all will understand why the agent crashed,as you see,the agent works
> well after I added some code to assure the POINTERs != NULL.Howerver,I'm
> not sure that what I did is right.so,you may help me ?
>
> And I've another question,How add my private MODULE to the default ? You
> konw,I mean when everyone use snmpget,snmpwalk and so forth to manipulate my
> private OID,there is no need to pass the argument "-m ALL" or something
> else equivalent.
>
> Also,in the agent,I've add the lines as follows to the file some.h
> config_require(rfw/rs)
> config_add_mib(RS-MIB)
> config_add_mib(RS-FW-MIB)
>
> Many thanks, Dave!
> Best wishes!
>
> Jiang
>
>
>
>
>
> On 12/22/06, Dave Shield <[email protected]> wrote:
> >
> > On 21/12/06, jiang jilin <[email protected]> wrote:
> > > I've found that agent crashed at function "myTable_handler ".Anynoe
> > can help
> > > me resolve the problem?
> >
> > Try running the agent under a debugger, or running the debugger
> > on the core file from the crash.   A backtrace should indicate
> > where exactly the crash is occuring.
> >   What does this code look like?
> >
> > Dave
> >
>
>

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