BIND 10 #1217: Error in automatically updating TTLs that do not match in an RRset

[BIND 10 Development]

#1217: Error in automatically updating TTLs that do not match in an RRset
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            Reporter:  jelte         |                        Owner:
                Type:  defect        |                       Status:  new
            Priority:  major         |                    Milestone:  New
           Component:  data source   |  Tasks
           Sensitive:  0             |                     Keywords:
         Sub-Project:  DNS           |              Defect Severity:  N/A
Estimated Difficulty:  0             |  Feature Depending on Ticket:
         Total Hours:  0             |          Add Hours to Ticket:  0
                                     |                    Internal?:  0
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 In our new datasource code, we automatically update the TTL of an RR if we
 are adding it to an RRset with a different TTL. This is fine in general,
 but we should not do it blindly; there may be more, but at least in the
 case of an RRSIG 'rrset' we shouldn't do it; RRSIGS for the same name can
 have a different TTL.

 For direct queries this is not much of a problem; we refuse direct RRSIG
 queries currently, and for covered types the TTL of the covered set is
 used.

 It would be a problem with AXFR out though (or, lower-level, the zone
 iterators). If we want to be as strict as possible, we should look at
 whether the covered types are equal too before modifying the TTL of RRSIG
 RRs. Or not check TTL for RRSIG at all.

 PS. Also played around with this for a bit, current AXFR IN modifies TTLs
 badly as well (though it gets fixed again when querying). Have not tried
 current AXFR out, but if the values are wrong in the database already it's
 probably not going to be good ;) Anyway with the refactor coming to an
 end, we should focus on the new stuff, and I don't think we need to fix
 the old one.

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Ticket URL: <http://bind10.isc.org/ticket/1217>
BIND 10 Development <http://bind10.isc.org>
BIND 10 Development