NAME

       snmpstrucfiller  -  snmpkit  functions  for  taking  making  snmp  requests  based  upon a
       structure.

SYNOPSIS

       #include <snmpkit.h>

       SNMPSTRUCTFILLER *new_snmpstructfiller(SNMPSESSION *session);
       void delete_snmpstructfiller(SNMPSTRUCTFILLER *doomed);
       void snmpstructfiller_append(SNMPSTRUCTFILLER *sf, const char *oidstr,Tags tag, unsigned int offset);
       void snmpstructfiller_remove(SNMPSTRUCTFILLER *sf,const char *oidstr);
       void *snmpstructfiller_get(SNMPSTRUCTFILLER *sf,void *tobefilled);
       void *snmpstructfiller_get_next(SNMPSTRUCTFILLER *sf, void *tobefilled);

DESCRIPTION

       A snmpstructfiller is an opaque data structure used fill C structures with data  from  the
       snmp requests.

       The  SNMP  protocol is designed in a way where there is significant overhead in process of
       encoding and exchanging a packet. Therefore it is very inefficient and time  consuming  to
       exchange many variables in individual request packets. The way around this is to bulk up a
       bunch of snmp requests into one packet. Since you are most frequently fetching information
       which  is  related the snmp structure filler is designed to associate the snmp objects and
       data types with the offsets into the structure. That way when you do a get or  a  get_next
       you will get back a completely filled in structure.

       The  new_snmpstructfiller()  function creates new structfiller. You will need one of these
       for every different set of objects that you want to fetch. It starts out  not  having  any
       requests   associated   with   it.   To   add   requests   to   this   structure  use  the
       snmpstructfiller_append()   function.   To   actually   do   the    request,    use    the
       snmpstructfiller_get() or the snmpstructfiller_get_next() functions.

       The  delete_snmpstructfiller()  function is the opposite of the new function. It frees all
       the resources used by  the structfiller structure.

       The snmpstructfiller_append() function appends a new snmp object to the structure  filler.
       It requires the oidstring.  This snmp library doesn't bother attempting to read MIBS.  You
       must specify the snmp object in dotted decimal notation. For  example,  system.sysDesc  is
       "1.3.6.1.2.1.1.1.0".  This  means that you must look up the objects ID's before hand. This
       sounds like a lot of work but I have found that when writing an application it  is  really
       not  that  much  of  a problem. The tag is the type of data that the object is supposed to
       have as defined in the MIB and cooresponds directly to the space used in the structure you
       are filling. The tag can be one of the following:

       INT_TAG long

       STRING_TAG char*

       IPADDR_TAG unsigned long
              You  get  the  IPADDR back in binary format. You must translate it byte for byte to
              get an IPADDR in the format that is usually expected.

       COUNTER_TAG long
              This could concievably be an unsigned long but enough implementations of  MIBS  are
              fouled  up in such that even though the mib specifies a counter, the device returns
              an integer. That it is best to store this number  in  an  integer  rather  than  an
              unsigned..

       TIME_TICK_TAG long

       The  final parameter is offset into the structure. For example if you have a structure and
       a variable like:
          struct info {
              char *descr; char *contact;
          } foo;

       Then the offset of descr  would  be  (char*)&(foo.descr)-(char*)&foo  and  the  offset  of
       contact  would  be (char*)&(foo.contact)-(char*)&foo I know that this is a very bad way of
       doing things and I intend to change it in the future. Probably what I will  do  is  change
       this to a function pointer which when called takes the pointer to the structure that it is
       supposed to insert the data in as well as the value of the data and it will insert it into
       the data into the structure.

AUTHOR

       Ben Woodard <ben@users.sourceforge.net>

BUGS

       The  library  can possibly throw different kinds of C++ exceptions that won't be caught by
       the glue code and therefore it can cause your program to crash inexplicably.

       There is no support for SNMP sets.

       There is no support for getting back an OID.

       There is no support for

SEE ALSO

       libsnmpkit(3), snmpsession(3), snmpsock(3), snmptable(3)