Wes: /* Running mib2c */

2011-07-19T02:54:47Z

‎Running mib2c

2011-07-18T23:15:37Z

‎Running mib2c

Wes: Created page with "{{MFDTutorial}} == Running mib2c == The first step is to generate the code. Create a new directory somewhere and run:

2011-07-13T21:52:39Z

Created page with "{{MFDTutorial}} == Running mib2c == The first step is to generate the code. Create a new directory somewhere and run: <table><tr><td width=20></td><td><td bgcolor=..."

New page
{{MFDTutorial}}

== Running mib2c ==

The first step is to generate the code. Create a new directory somewhere
and run:

<table><tr><td width=20></td><td><td bgcolor=CCCCCC>
$ mib2c -c mfd-top.m2c ifXTable
writing to ifXTable.h
| +-> Processing table ifXTable
writing to -
There are no defaults for ifXTable. Would you like to

1) Accept hard-coded defaults [DEFAULT]
2) Set defaults now

Select your choice : 2

</td><td>
Notes: Select '2', to change some of the defaults.
</td></tr><tr><td width=20></td><td><td bgcolor=CCCCCC>

This table has writable columns. Do you want to generate
code for writeable columns, or restrict the table to read-only?

1) generate code with writeable columns [DEFAULT]
2) generate code with read-only columns

Select your choice : [RETURN]

</td><td>
Notes: We will be implementing set support.
</td></tr><tr><td width=20></td><td><td bgcolor=CCCCCC>

Writable tables sometimes have dependencies beteen columns
or with other tables. If there are no dependencies in this table, you
might want the extra code.

1) do not generate dependency code [DEFAULT]
2) generate dependency code

Select your choice : [RETURN]

</td><td>
Notes: While the ifXTable is related to the ifTable, the two tables do
not have any dependencies.
</td></tr><tr><td width=20></td><td><td bgcolor=CCCCCC>

Do you want to use an existing data structure for the USER context?

1) No, use netsnmp_data_list * [DEFAULT]
2) Yes, use my own structure

Select your choice : [RETURN]

</td><td>
Notes: We don't need to track anything at the table level, so
we'll just accept the default.
</td></tr><tr><td width=20></td><td><td bgcolor=CCCCCC>

Do you want to use an existing data structure for the DATA context?

1) No, use generated [DEFAULT]
2) Yes, use my own structure

Select your choice : 2
Enter your DATA context : netsnmp_interface_entry

</td><td>
Notes: We'll be using the net-snmp access routines to get interface
data, so we'll just use the netsnmp_interface_entry structure to
keep that data.
</td></tr><tr><td width=20></td><td><td bgcolor=CCCCCC>

Do you want to allocate your 'netsnmp_interface_entry', or
embed it directly?

1) directly embed structure [DEFAULT]
2) dynamically allocate structure

Select your choice : 2

</td><td>
Notes: The net-snmp access routines will provide us with allocated
structures, so we'll just use those instead of copying them to an
embeded structure.
</td></tr><tr><td width=20></td><td><td bgcolor=CCCCCC>

Do you need to initialize elements in your 'netsnmp_interface_entry'
when a new instance is created?

1) no, no initialization needed [DEFAULT]
2) yes, initilization is needed

Select your choice : [RETURN]

</td><td>
Notes: We'll be using the net-snmp data access routines to create
the netsnmp_interface_entry structures, and those routines will
take care of initialization for us.
</td></tr><tr><td width=20></td><td><td bgcolor=CCCCCC>

Which method would you like to use to gather data about available rows?

1) container-cached : [DEFAULT] This access method uses a
netsnmp_container to keep track of the indexes (and data, usually)
for each row. Thi method is best for:
- Internal data (maintained by the agent)
- External data (maintained by another process) which can be
cached (minumum cache time is 1 second)

2) unsorted-external : This access method iterates over all of your data
to find the row with the appropriate index. This method is best for
- External data that cannot be cached.

Select your choice : [RETURN]

</td><td>
Notes: We are going to keep a cache and refresh it periodically.
</td></tr><tr><td width=20></td><td><td bgcolor=CCCCCC>

When accessing your data, is your data TRANSIENT?

1) Yes. My data is TRANSIENT (e.g. a pointer to a static buffer that
my be overwritten during a request) and needs to be copied during
processing.

2) Yes. My data is SEMI-TRANSIENT (e.g. an allocated pointer to a
copy of the data).

3) No, my data is PERSISTENT (e.g. an allocated pointer to the actual
data, which is under the agent's control)

Select your choice [DEFAULT=1] : 2

</td><td>
Notes: We get a copy of the interface data via the netsnmp data access
functions.
</td></tr><tr><td width=20></td><td><td bgcolor=CCCCCC>

Do you want example code to be generated?

1) generate example code [DEFAULT]
2) do not generate example code

Select your choice : 2
</td><td>
Notes: We saw the example code in the last tutorial, so we'll skip
it this time.
</td></tr></table>

As before, when finished, you should have several files:

* ifXTable.c
* ifXTable_data_access.c
* ifXTable_data_access.h
* ifXTable_data_get.c
* ifXTable_data_get.h
* ifXTable_data_set.c
* ifXTable_data_set.h
* ifXTable_enums.h
* ifXTable.h
* ifXTable_interface.c
* ifXTable_interface.h
* ifXTable_Makefile
* ifXTable_oids.h
* ifXTable-README-FIRST.txt
* ifXTable-README-ifXTable.txt
* ifXTable_subagent.c

You should read ''ifXTable-README-FIRST.txt'' for a basic overview
of MFD. The basic steps outlined in
''ifXTable-README-ifXTable.txt'' were used to write this tutorial.

@@ Line 69: / Line 69: @@
 </td><td>
-Notes:<br> We'll be using the net-snmp access routines to get interface
+Notes:<br> We'll be using the ifTable's access routines to get interface
 data, so we'll just use the netsnmp_interface_entry structure to
 keep that data.

@@ Line 7: / Line 7: @@
 <table><tr><td width=20></td><td><td bgcolor=CCCCCC>
-   $ <font color=blue>mib2c -c mfd-top.m2c ifXTable</font>
+   $ <font color=blue>mib2c -c mib2c.mfd.conf ifXTable</font>
    writing to ifXTable.h
    | +-> Processing table ifXTable