BIND 10 #145: DNAME-CNAME synthesis can throw if the result is too long.

[BIND 10 Development]

#145: DNAME-CNAME synthesis can throw if the result is too long.
-------------------------+--------------------------------------------------
 Reporter:  jinmei       |        Owner:  UnAssigned
     Type:  defect       |       Status:  reviewing 
 Priority:  critical     |    Milestone:            
Component:  data source  |   Resolution:            
 Keywords:               |    Sensitive:  0         
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Comment(by jinmei):

 Replying to [comment:3 each]:

 As noted in the ticket, BIND 9 returns an YXDOMAIN rcode.
 {{{
                                 /*
                                  * RFC2672, section 4.1, subsection 3c
 says
                                  * we should return YXDOMAIN if the
 constructed
                                  * name would be too long.
                                  */
                                 client->message->rcode =
 dns_rcode_yxdomain;
 }}}

 If the RFC says this, we should follow it.

 I'd also add another test on the boundary condition: the case where the
 synthesized name has the possible maximum length.

 And please add a comment about the condition:
 {{{
     if (prefix.getLength() + dname_target.getLength() - 1 >
 Name::MAX_WIRE) {
 }}}
 because why we need "- 1" may not be so obvious.

-- 
Ticket URL: <https://bind10.isc.org/ticket/145#comment:4>
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