BIND 10 #2000: update libdns++ OPT RDATA so it can handle EDNS options

[BIND 10 Development]

#2000: update libdns++ OPT RDATA so it can handle EDNS options
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            Reporter:  jinmei        |                        Owner:  muks
                Type:  enhancement   |                       Status:
            Priority:  medium        |  reviewing
           Component:  libdns++      |                    Milestone:
            Keywords:                |  bind10-1.2-release-freeze
           Sensitive:  0             |                   Resolution:
         Sub-Project:  DNS           |                 CVSS Scoring:
Estimated Difficulty:  4             |              Defect Severity:  N/A
         Total Hours:  0             |  Feature Depending on Ticket:  NSID
                                     |          Add Hours to Ticket:  0
                                     |                    Internal?:  0
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Changes (by stephen):

 * owner:  stephen => muks


Comment:

 Reviewed commit 916893ac37eeeb169c90c7cf374630a7cfba127b

 '''src/lib/dns/rdata/generic/opt_41.h'''
 '''src/lib/dns/rdata/generic/opt_41.cc'''
 The methods (and attributes) of both OPT and the internal PseudoRR class
 need documentation.

 The storage of the pseudo-RRs as a vector of shared pointers to PseudoRR
 objects seems a bit  complicated, since only the getPseudoRRs () method
 accesses them. Why not store the PseudoRRs as a vector of bytes?  This
 would would simplify the construction (which only needs to check that the
 lengths in the input buffer indicate that the buffer could represent a set
 of PseudoRRs), the toWire() methods (which just write out the buffer as a
 set of bytes) and append() method (which just appends the code, length and
 data to the current buffer). Only the getPseudoRRs() method need be
 altered to split the buffer into a vector of PseudoRR objects, the code of
 which is already in the constructor.  (Of course, this suggestion depends
 on the anticipated usage - if getPseudoRRs() is called more frequently
 than anything else, the current approach would reduce overhead.)

 '''src/lib/dns/tests/rdata_opt_unittest.cc'''
 In the test data (as indicated in rdata_opt_wiredata), I would suggest
 making the numeric values of the option code and the length different.  If
 there is some error in the source code that gets the option's code and
 length confused, it won't show up in a test using that data.


 '''src/lib/dns/tests/testdata/rdata_opt_fromWire{1,2,3,4}'''
 Please start comments with a capital letter.

 '''src/lib/dns/tests/testdata/rdata_opt_fromWire{3,4}'''
 s/psuedo/pseudo/

 '''Other'''
 Suggested !ChangeLog entry is OK

-- 
Ticket URL: <https://bind10.isc.org/ticket/2000#comment:6>
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