[erlang-patches] Bugfix to snmpTargetAddrExtTable

[Stefan Zegenhagen]

Dear all,

snmpTargetAddrExtTable instrumentation in snmp_community_mib.erl can
pass error return values with invalid column numbers to the SNMP engine
in response to set requests. The problem arises as follows:

      * snmpTargetAddrExtTable columns are stored in the appropriate row
        of snmpTargetAddrTable starting at column 11
      * snmpTargetAddrExtTable instrumentation does some basic checks of
        the column data in set requests, adds 10 to each column number
        (maps to the corresponding columns in snmpTargetAddrTable
        storage) and passes the data to the generic SNMP table handler,
        changing the table name to snmpTargetAddrTable
      * errors from the generic SNMP table handler are returned as-is,
        including column numbers+10
      * the SNMP engine detects invalid column numbers returned from
        snmpTargetAddrExtTable instrumentation and emits a genErr error
        report

The resulting genErr obscures the real problem behind the set-request.

The patch attached to this e-mail solves the problem by inspecting the
result from the generic SNMP table handler and by converting the column
numbers back to the allowed range in case of error responses.


Kind regards,

-- 
Dr. Stefan Zegenhagen

arcutronix GmbH
Garbsener Landstr. 10
30419 Hannover
Germany

Tel:   +49 511 277-2734
Fax:   +49 511 277-2709
Email: stefan.zegenhagen@REDACTED
Web:   www.arcutronix.com

*Synchronize the Ethernet*

General Managers: Dipl. Ing. Juergen Schroeder, Dr. Josef Gfrerer -
Legal Form: GmbH, Registered office: Hannover, HRB 202442, Amtsgericht
Hannover; Ust-Id: DE257551767.

Please consider the environment before printing this message.
-------------- next part --------------
A non-text attachment was scrubbed...
Name: 0001-SNMP-fix-invalid-return-values-from-snmpTargetAddrEx.patch
Type: text/x-patch
Size: 2229 bytes
Desc: not available
URL: <http://erlang.org/pipermail/erlang-patches/attachments/20120903/700248bf/attachment.bin>