GENSNMPTREE(1)

NAME
gensnmptree - generate C and header files from a MIB description file

SYNOPSIS
gensnmptree [-helt] [-p prefix] [name ...]

DESCRIPTION
The gensnmptree utility is used to either generate C language tables and header files from a MIB description or to numeric OIDs from MIB descriptions. The first form is used only for maintaining the bsnmpd(1) daemon or for module writers. The second form may be used by SNMP client program writers.

If the -e option is not used gensnmptree reads a MIB description from its standard input and creates two files: a C-file prefixtree.c containing a table used by bsnmpd(1) during PDU processing and a header file prefixtree.h containing appropriate declarations of the callback functions used in this table and the table itself.

If the -e option is specified gensnmptree expects MIB variable names (only the last component) on its command line. It reads a MIB specification from standard input and for each MIB variable name emits three C preprocessor defines on its standard output:

OIDX_name
    This define can be used to initialize a struct asn_oid in the following way:

        const struct asn_oid oid_sysDescr = OIDX_sysDescr;

OIDLEN_name
    is the length of the OID.

OID_name
    is the last component of the OID.

The options are as follows:

-h  Print a short help page.

-e  Enter extract mode.

-l  Generate local preprocessor includes. This is used for bootstrapping bsnmpd(1).

-t  Instead of normal output print the resulting tree.

-p prefix
    Prefix the file names and the table name with prefix.

MIBS
The syntax of the MIB description file can formally be specified as follows:

    file := tree | tree file
    tree := head elements ')'
    entry := head ':' index STRING elements ')'
    leaf := head TYPE STRING ACCESS ')'
    column := head TYPE ACCESS ')'
    head := '(' INT STRING
    elements := EMPTY | elements element
    element := tree | leaf
    index := TYPE | index TYPE

TYPE specifies a SNMP data type and may be one of
•   NULL
•   INTEGER
•   INTEGER32 (same as INTEGER)
•   UNSIGNED32 (same as GAUGE)
•   OCTETSTRING
•   IPADDRESS
•   OID
•   TIMETICKS
•   COUNTER
•   GAUGE
•   COUNTER64

ACCESS specifies the accessibility of the MIB variable (which operation can be performed) and is one of
•   GET
•   SET

INT is a decimal integer and STRING is any string starting with a letter or underscore and consisting of letters, digits and underscores, that is not one of the keywords.

EXAMPLES
The following MIB description describes the system group:

    (1 internet
      (2 mgmt
        (1 mibII
          (1 system
            (1 sysDescr OCTETSTRING op_system_group GET)
            (2 sysObjectId OID op_system_group GET)
            (3 sysUpTime TIMETICKS op_system_group GET)
            (4 sysContact OCTETSTRING op_system_group GET SET)
            (5 sysName OCTETSTRING op_system_group GET SET)
            (6 sysLocation OCTETSTRING op_system_group GET SET)
            (7 sysServices INTEGER op_system_group GET)
            (8 sysORLastChange TIMETICKS op_system_group GET)
            (9 sysORTable
              (1 sysOREntry : INTEGER op_or_table
                (1 sysORIndex INTEGER)
                (2 sysORID OID GET)
                (3 sysORDescr OCTETSTRING GET)
                (4 sysORUpTime TIMETICKS GET)
            ))
          )
        )
      )
    )

SEE ALSO
bsnmpd(1)

AUTHORS
Hartmut Brandt <harti@freebsd.org>