Raises ArgumentError when trying to parse an invalid CAA record

[nsmethwick-fastly]

When a CAA record is incorrectly formatted dnsruby throws a NoMethod error.

kdig +bufsize=1280 @8.8.8.8 -t CAA buda.com
;; ->>HEADER<<- opcode: QUERY; status: NOERROR; id: 44583
;; Flags: qr rd ra ad; QUERY: 1; ANSWER: 15; AUTHORITY: 0; ADDITIONAL: 1
;; EDNS PSEUDOSECTION:
;; Version: 0; flags: ; UDP size: 512 B; ext-rcode: NOERROR
;; QUESTION SECTION:
;; buda.com.                IN  CAA
;; ANSWER SECTION:
buda.com.               451 IN  CAA 0 comodoca.com "issue"
buda.com.               451 IN  CAA 0 comodoca.com "issuewild"
buda.com.               451 IN  CAA 0 digicert.com "issue"
buda.com.               451 IN  CAA 0 digicert.com "issuewild"
buda.com.               451 IN  CAA 0 issue "comodoca.com"
buda.com.               451 IN  CAA 0 issue "digicert.com; cansignhttpexchanges=yes"
buda.com.               451 IN  CAA 0 issue "letsencrypt.org"
buda.com.               451 IN  CAA 0 issue "pki.goog; cansignhttpexchanges=yes"
buda.com.               451 IN  CAA 0 issuewild "comodoca.com"
buda.com.               451 IN  CAA 0 issuewild "digicert.com; cansignhttpexchanges=yes"
buda.com.               451 IN  CAA 0 issuewild "letsencrypt.org"
buda.com.               451 IN  CAA 0 issuewild "pki.goog; cansignhttpexchanges=yes"
buda.com.               451 IN  CAA 0 letsencrypt.com "issue"
buda.com.               451 IN  CAA 0 letsencrypt.com "issuewild"
buda.com.               451 IN  CAA 0 [email protected] "iodef"

It does look like a thread error that appears to be related seems to get raised. I am not sure if anything additional needs to be added to this to handle that error but I am happy to provide more information if needed:

resolver.query("buda.com", "CAA")

<Thread:0x0000000116149828 /Users/nsmethwick/.gem/ruby/3.0.5/gems/dnsruby-1.72.1/lib/dnsruby/select_thread.rb:69 run> terminated with exception (report_on_exception is true):
/Users/nsmethwick/.gem/ruby/3.0.5/gems/dnsruby-1.72.1/lib/dnsruby/select_thread.rb:625:in `block in send_exception_to_client': undefined method `client_queue' for nil:NilClass (NoMethodError)
	from /Users/nsmethwick/.gem/ruby/3.0.5/gems/dnsruby-1.72.1/lib/dnsruby/select_thread.rb:624:in `synchronize'
	from /Users/nsmethwick/.gem/ruby/3.0.5/gems/dnsruby-1.72.1/lib/dnsruby/select_thread.rb:624:in `send_exception_to_client'
	from /Users/nsmethwick/.gem/ruby/3.0.5/gems/dnsruby-1.72.1/lib/dnsruby/select_thread.rb:569:in `rescue in get_incoming_data'
	from /Users/nsmethwick/.gem/ruby/3.0.5/gems/dnsruby-1.72.1/lib/dnsruby/select_thread.rb:513:in `get_incoming_data'
	from /Users/nsmethwick/.gem/ruby/3.0.5/gems/dnsruby-1.72.1/lib/dnsruby/select_thread.rb:280:in `block in process_ready'
	from /Users/nsmethwick/.gem/ruby/3.0.5/gems/dnsruby-1.72.1/lib/dnsruby/select_thread.rb:275:in `each'
	from /Users/nsmethwick/.gem/ruby/3.0.5/gems/dnsruby-1.72.1/lib/dnsruby/select_thread.rb:275:in `process_ready'
	from /Users/nsmethwick/.gem/ruby/3.0.5/gems/dnsruby-1.72.1/lib/dnsruby/select_thread.rb:219:in `do_select'
	from /Users/nsmethwick/.gem/ruby/3.0.5/gems/dnsruby-1.72.1/lib/dnsruby/select_thread.rb:69:in `block (2 levels) in initialize'
/Users/nsmethwick/.gem/ruby/3.0.5/gems/dnsruby-1.72.1/lib/dnsruby/resource/CAA.rb:47:in `from_string': undefined method `[]' for nil:NilClass (NoMethodError)
	from /Users/nsmethwick/.gem/ruby/3.0.5/gems/dnsruby-1.72.1/lib/dnsruby/resource/RR.rb:113:in `initialize'
	from /Users/nsmethwick/.gem/ruby/3.0.5/gems/dnsruby-1.72.1/lib/dnsruby/resource/CAA.rb:68:in `new'
	from /Users/nsmethwick/.gem/ruby/3.0.5/gems/dnsruby-1.72.1/lib/dnsruby/resource/CAA.rb:68:in `decode_rdata'
	from /Users/nsmethwick/.gem/ruby/3.0.5/gems/dnsruby-1.72.1/lib/dnsruby/message/decoder.rb:171:in `block in get_rr'
	from /Users/nsmethwick/.gem/ruby/3.0.5/gems/dnsruby-1.72.1/lib/dnsruby/message/decoder.rb:53:in `get_length16'
	from /Users/nsmethwick/.gem/ruby/3.0.5/gems/dnsruby-1.72.1/lib/dnsruby/message/decoder.rb:171:in `get_rr'
	from /Users/nsmethwick/.gem/ruby/3.0.5/gems/dnsruby-1.72.1/lib/dnsruby/message/message.rb:574:in `block (2 levels) in decode'
	from /Users/nsmethwick/.gem/ruby/3.0.5/gems/dnsruby-1.72.1/lib/dnsruby/message/message.rb:573:in `times'
	from /Users/nsmethwick/.gem/ruby/3.0.5/gems/dnsruby-1.72.1/lib/dnsruby/message/message.rb:573:in `block in decode'
	from /Users/nsmethwick/.gem/ruby/3.0.5/gems/dnsruby-1.72.1/lib/dnsruby/message/decoder.rb:20:in `initialize'
	from /Users/nsmethwick/.gem/ruby/3.0.5/gems/dnsruby-1.72.1/lib/dnsruby/message/message.rb:567:in `new'
	from /Users/nsmethwick/.gem/ruby/3.0.5/gems/dnsruby-1.72.1/lib/dnsruby/message/message.rb:567:in `decode'
	from /Users/nsmethwick/.gem/ruby/3.0.5/gems/dnsruby-1.72.1/lib/dnsruby/select_thread.rb:514:in `get_incoming_data'
	from /Users/nsmethwick/.gem/ruby/3.0.5/gems/dnsruby-1.72.1/lib/dnsruby/select_thread.rb:280:in `block in process_ready'
	from /Users/nsmethwick/.gem/ruby/3.0.5/gems/dnsruby-1.72.1/lib/dnsruby/select_thread.rb:275:in `each'
	from /Users/nsmethwick/.gem/ruby/3.0.5/gems/dnsruby-1.72.1/lib/dnsruby/select_thread.rb:275:in `process_ready'
	from /Users/nsmethwick/.gem/ruby/3.0.5/gems/dnsruby-1.72.1/lib/dnsruby/select_thread.rb:219:in `do_select'
	from /Users/nsmethwick/.gem/ruby/3.0.5/gems/dnsruby-1.72.1/lib/dnsruby/select_thread.rb:69:in `block (2 levels) in initialize'

Let me know if I did this right or if you'd prefer to handle this in a different way.

[alexdalitz]

@nsmethwick-fastly Thank you very much for this!
It looks good - the only thing I would ask you, please, to change would be to raise a Dnsruby DecodeError rather than an ArgumentError, to keep it in line with the rest of the RR parsing errors.
Thanks!

[nsmethwick-fastly]

@alexdalitz updated!

[alexdalitz]

@nsmethwick-fastly Merged - thank you!