[netmod] Problem in draft-ietf-netmod-smi-yang-04

Martin Bjorklund <mbj@tail-f.com> Mon, 02 April 2012 14:13 UTC

Date: Mon, 02 Apr 2012 16:13:33 +0200
Message-Id: <20120402.161333.1154244105910951530.mbj@tail-f.com>
To: netmod@ietf.org, bclaise@cisco.com
From: Martin Bjorklund <mbj@tail-f.com>
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Subject: [netmod] Problem in draft-ietf-netmod-smi-yang-04
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Hi,

I just discovered a problem with draft-ietf-netmod-smi-yang-04.  I
believe this document has been sent to the IESG.


The document specifies how to translate an OCTET STRING w/
DISPLAY-HINT to a YANG 'string'.  But look at this example:

InetAddressIPv4 ::= TEXTUAL-CONVENTION
    DISPLAY-HINT "1d.1d.1d.1d"
    STATUS       current
    DESCRIPTION
        "Represents an IPv4 network address:

           Octets   Contents         Encoding
            1-4     IPv4 address     network-byte order

         The corresponding InetAddressType value is ipv4(1).

         This textual convention SHOULD NOT be used directly in object
         definitions, as it restricts addresses to a specific format.
         However, if it is used, it MAY be used either on its own or in
         conjunction with InetAddressType, as a pair."
    SYNTAX       OCTET STRING (SIZE (4))

becomes:

  typedef InetAddressIPv4 {
    type string {
      length "4";
      ...
    }
    ...
  }

But the length of an ipv4 address is not 4 characters!!

Conclusion: if the type is octet string, and it has a display-hint, we
must not translate the length restriction to yang.


/martin

[netmod] Problem in draft-ietf-netmod-smi-yang-04 Martin Bjorklund
Re: [netmod] Problem in draft-ietf-netmod-smi-yan… Juergen Schoenwaelder
Re: [netmod] Problem in draft-ietf-netmod-smi-yan… Martin Bjorklund