copyHeader() is redundant, we allocate a header and then copy the
non-pointer elements into it; we don't need to do this, because if we
just asssign rr.Hdr to something else we get the same result.
Remove copyHeader() and the generation and use of it in ztypes.go.
* Cleanup and removals
Gut rawmsg.go as most functions are not used. Reword some documentation.
Add more types to be checked for name compression.
* Yeah, we do use these
* Remove this function as well - only used one
Add dns:txt parsing helper to prevent compile errors. This allows
us to generate all unpack/pack function.
Add pack to the RR interface definition and add this method to
PrivateRR.
We still use typeToUnpack to select which types don't use reflection.
Formatters are not needs you can access the members just fine.
However the rdata Field access function are handy and non-trivial,
extend them and add a basic test.
The dns package implements String() for all RR types, but sometimes you will
need more flexibility. The functions Printf, Sprintf, etc. implemented formatted I/O
for the RR type.
Printing
The verbs:
Generic part of RRs:
%N the owner name of the RR
%C the class: IN, CH, CLASS15, etc.
%D the TTL in seconds
%Y the type: MX, A, etc.
The rdata of each RR differs, we allow each field to be printed as a string.
Rdata:
%0 the first rdata field
%1 the second rdata field
%2 the third rdata field
.. ...
%9 the nineth rdata field
%R all rdata fields
The rdata fields remain a TODO, but will be implemented using
reflection.
Changes to domain name packing and unpacking:
* Escape dot, backslash, brackets, double-quote, semi-colon and space
* Tab, line feed and carriage return become \t, \n and \r
Changes to TXT string packing and unpacking:
* Escape backslash and double-quote
* Tab, line feed and carriage return become \t, \n and \r
* Other unprintables to \DDD
Stringers do the equivalent of putting domain names and TXT strings
to the wire and back.
There is some duplication of logic. I found performance suffered when
I broke the logic out into smaller functions. I think this may have
been due to functions not being inlined for various reasons.