Re: vacmViewTreeFamilySubtree missing SIZE restriction

HI,

Without specific text saying you can put a SIZE sub-clause on 
an OID type specification in the SMI, you cannot specify
a SIZE sub-clause, since it is not legal in ASN.1!
(And there is no such text in the SMI that says it is valid.)

Note, however, it is perfectly legal, AND APPROPRIATE, to
put constraints on the values for data type OID that
is specified in the SYNTAX clause. Again, there is no
valid way to specify this with parsable contraints in
the current MIB module language that is specified in the
SMI documents! You must do this in the DESCRIPTION clause
for the OBJECT-TYPE or TEXTUAL-CONVENTION definition.

At 11:23 AM 1/13/2003 -0800, Xiang Li wrote:

>Hi, 
>
>In rfc2578
>
>9.  Refined Syntax
>
>   Some macros have clauses which allows syntax to be refined,
>   specifically: the SYNTAX clause of the OBJECT-TYPE macro, and the
>   SYNTAX/WRITE-SYNTAX clauses of the MODULE-COMPLIANCE and AGENT-
>   CAPABILITIES macros [2].  However, not all refinements of syntax are
>   appropriate.  In particular, the object's primitive or application
>   type must not be changed.
>
>   Further, the following restrictions apply:
>
>                          Restrictions to Refinement of
>     object syntax         range   enumeration     size
>     -----------------     -----   -----------     ----
>               INTEGER      (1)        (2)           -
>             Integer32      (1)         -            -
>            Unsigned32      (1)         -            -
>          OCTET STRING       -          -           (3)
>
>     OBJECT IDENTIFIER       -          -            -
>
>
>***Note:  OBJECT IDENTIFIER should not be refined...***
>
>
>
> No other types of refinements can be specified in the SYNTAX clause.
>   However, the DESCRIPTION clause is available to specify additional
>   restrictions which can not be expressed in the SYNTAX clause.
>   Further details on (and examples of) sub-typing are provided in
>   Appendix A.
>
>
>On Sat, 11 Jan 2003, Michael Kirkham wrote:
>
>> 
>> Hi, all.  My MIB compiler work picked upon the following error in RFC
>> 3415, which is also present in 2575 and 2275:
>> 
>> rfc3415.mib [SNMP-VIEW-BASED-ACM-MIB:vacmViewTreeFamilyEntry] : error :
>> INDEX object 'vacmViewTreeFamilySubtree' value may exceed maximum of 128
>> subidentifiers for OBJECT IDENTIFIER length.
>> 
>> The RFC 3415 definition is:
>> 
>> vacmViewTreeFamilySubtree OBJECT-TYPE
>>     SYNTAX       OBJECT IDENTIFIER
>>     MAX-ACCESS   not-accessible
>>     STATUS       current
>>     DESCRIPTION "The MIB subtree which when combined with the
>>                  corresponding instance of vacmViewTreeFamilyMask
>>                  defines a family of view subtrees.
>>                 "
>>     ::= { vacmViewTreeFamilyEntry 2
>> 
>> I believe it should be:
>> 
>>     SYNTAX       OBJECT IDENTIFIER (SIZE(2..84))
>> 
>> --
>> Michael Kirkham
>> www.muonics.com
>> 
>
>-- 
>      ; Regards
>             --Xiang Li-- 

Regards,
/david t. perkins