Compaq AAR04BCTE manual Including the Routines and Building the Subagent

Creating a Subagent Using the eSNMP API

3.3 Creating a MIB Source File

3. Initialized Subtree Structure Section

The third section of the subtree_TBL.C file is the SUBTREE structure itself. A pointer to this structure is passed to the eSNMP library routine esnmp_register to register the subtree. It is through this pointer that the library routines find the object structures. The following is an example of the chess subtree structure:

SUBTREE chess_subtree = { "chess", "1.3.6.1.4.1.36.2.15.2.99",

{ 11, &elems[0] }, objects, I_moveStatus};

The following table describes the elements of the SUBTREE structure, the definition of each element in the header file (subtree_TBL.H)), and the element in the chess example:

	Header File
Description	Representation	Example
The name of the subtree’s base	name	"chess"
element.
The ASCII string representation	dots	"1.3.6.1.4.1.36.2.15.2.99"
of the subtree’s OID. This is what
actually gets registered.

The OID structure for the base node of the subtree. This points back to the array of integers.

oid 11, &elems[0] }

A pointer to the array of objects	object_oid	objects
in the object table. It is indexed
by the I_xxxx definitions found in
the subtree_TBL.H file.
The index of the last object in the	last	I_moveStatus
object_TBL file. This is used to
determine when the end of the
table has been reached.

4. Routines Section

The final section of the subtree_TBL.C file. contains short routines for allocating and freeing the mib_group_type. These are provided as a convenience and are not a required part of the API.

3.4 Including the Routines and Building the Subagent

The MIB compiler does not generate code for implementing the method routines for your subagent. This includes code for processing get, set, and other SNMP requests as well as for generating traps. You must write this code yourself. See the CHESS_MIB.C module for an example.

To produce executable subagent code, follow these steps:

1.Compile the C modules generated by the MIB compiler, along with your implementation code. Use a command in the following format (derived from the sample provided for building the chess example in TCPIP$BUILD_ CHESS.COM):

$ CC /INCLUDE=TCPIP$SNMP /PREFIX=ALL /STANDARD=VAX CHESS_METHOD.C, - _$ CHESS_MIB.C, CHESS_TBL.C

Creating a Subagent Using the eSNMP API 3–11