Handle name-error/NXDOMAIN when looking up nameservers

This commit is contained in:
Tony Garnock-Jones 2012-02-17 21:32:56 -05:00
parent bee10f5cdd
commit b991160eab
1 changed files with 20 additions and 17 deletions

View File

@ -195,9 +195,12 @@
(set-union u1 u2)
(set-union d1 d2)))
;; DomainName CompleteAnswer -> ListOf<IPv4>
;; DomainName Maybe<CompleteAnswer> -> SetOf<IPv4>
(define (extract-addresses name ans)
(match-define (complete-answer ns us ds) ans)
(match ans
[#f ;; name-error/NXDOMAIN, so definitely no addresses.
(set)]
[(complete-answer ns us ds)
(define rrs (set->list (set-union ns us ds)))
(let loop ((names (list name))
(ips (set))
@ -212,4 +215,4 @@
(cname-records (filter (lambda (rr) (equal? 'cname (rr-type rr))) records)))
(loop (append (map rr-rdata cname-records) (cdr names))
(set-union ips (list->set (map rr-rdata a-records)))
(set-add seen name))))))))
(set-add seen name)))))))]))