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First pass at stripping types

This commit is contained in:
Tony Garnock-Jones 2014-08-06 21:58:50 -07:00
parent fd73114fc3
commit dc3df20d9b
11 changed files with 380 additions and 580 deletions
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4
api-untyped.rkt
View File

@ -22,7 +22,9 @@
(require marketplace/struct-map)
(provide (struct-out domain))
(provide (struct-out domain)
downcase-labels
make-domain)
;; (These utilities need to be defined ahead of the domain struct
;; definition.)

185
api.rkt
View File

@ -1,4 +1,4 @@
#lang typed/racket/base
#lang racket/base
;; Definitions for use in the API to the functionality of the library.
;;
;;; Copyright 2010, 2011, 2012, 2013 Tony Garnock-Jones <tonyg@ccs.neu.edu>
@ -19,18 +19,12 @@
;;; along with marketplace-dns. If not, see
;;; <http://www.gnu.org/licenses/>.
(provide DomainName
(except-out (struct-out domain) domain)
(provide (except-out (struct-out domain) domain)
(rename-out [make-domain domain])
domain-root?
domain-parent
IPv4
IPv6
(struct-out question-repr)
Question question question?
QuestionPattern question-pattern question-pattern?
(struct-out question)
question-cyclic?
question-too-glueless?
@ -39,19 +33,14 @@
cname-question
ns-question
(struct-out answered-question-repr)
AnsweredQuestion answered-question answered-question?
AnsweredQuestionPattern answered-question-pattern answered-question-pattern?
(struct-out answered-question)
(struct-out rr)
RR
CompleteAnswer
(struct-out complete-answer)
empty-complete-answer
merge-answers
extract-addresses
RData
(struct-out rdata)
(struct-out rdata-domain)
(struct-out rdata-ipv4)
@ -66,10 +55,6 @@
(struct-out rdata-raw)
rdata-type-pred
RRType
QueryType
RRClass
QueryClass
type->value value->type
qtype->value value->qtype
class->value value->class
@ -80,48 +65,29 @@
(require racket/match)
(require marketplace)
(require marketplace/struct-map)
(require marketplace/support/pseudo-substruct)
;; A DomainName is a (domain ListOf<Bytes>), representing a domain
;; name. The head of the list is the leftmost label; for example,
;; www.google.com is represented as '(#"www" #"google" #"com").
(require/typed "api-untyped.rkt"
[#:struct domain ([labels : (Listof Bytes)]
[downcased-labels : (Listof Bytes)])])
(define-type DomainName domain)
(require "api-untyped.rkt")
;; A ShortString is a String with length 255 or shorter.
;; An IPv4 is a (vector Byte Byte Byte Byte), representing an IPv4
;; address. For example, 127.0.0.1 is represented as (vector 127 0 0
;; 1).
(define-type IPv4 (Vector Byte Byte Byte Byte))
;; An IPv6 is a Vector of length 16 containing Bytes, representing an
;; IPv6 address. For example, 2001:0db8:85a3:0000:0000:8a2e:0370:7334
;; is represented as (vector #x20 #x01 #x0d #xb8 #x85 #xa3 #x00 #x00
;; #x00 #x00 #x8a #x2e #x03 #x70 #x73 #x34).
(define-type IPv6 (Vector Byte Byte Byte Byte
Byte Byte Byte Byte
Byte Byte Byte Byte
Byte Byte Byte Byte))
;; A Question is a (question DomainName QueryType QueryClass
;; QuestionContext), representing a DNS question: "What are the RRs
;; for the given name, type and class?" as well as a possible parent
;; question that the answer to this question is to contribute to the
;; answer to.
(struct: (TName TType TClass TContext)
question-repr
([name : TName] [type : TType] [class : TClass] [context : TContext])
#:transparent)
(pseudo-substruct: (question-repr DomainName QueryType QueryClass QuestionContext)
Question question question?)
(pseudo-substruct: (question-repr (U Wild DomainName)
(U Wild QueryType)
(U Wild QueryClass)
(U Wild QuestionContext))
QuestionPattern question-pattern question-pattern?)
(struct question (name type class context) #:transparent)
;; A QuestionContext is one of
;; -- (cname-subq Question), resulting from the expansion of a CNAME
@ -134,33 +100,20 @@
;; excessively-glueless subquestion not represented here, and should
;; *not* in turn be considered for gluelessness-restarting: this is
;; needed to avoid a different kind of infinite loop.
(struct: subquestion ([parent : Question]) #:transparent)
(struct: cname-subq subquestion () #:transparent)
(struct: ns-subq subquestion () #:transparent)
(define-type QuestionContext (U subquestion cname-subq ns-subq False 'restart))
(struct subquestion (parent) #:transparent)
(struct cname-subq subquestion () #:transparent)
(struct ns-subq subquestion () #:transparent)
;; An AnsweredQuestion is an (answered-question Question
;; Maybe<CompleteAnswer>).
(struct: (TQ TA) answered-question-repr ([q : TQ] [a : TA]) #:transparent)
(pseudo-substruct: (answered-question-repr Question (Option CompleteAnswer))
AnsweredQuestion answered-question answered-question?)
(pseudo-substruct: (answered-question-repr (U Wild Question) (U Wild (Option CompleteAnswer)))
AnsweredQuestionPattern answered-question-pattern answered-question-pattern?)
(struct answered-question (q a) #:transparent)
;; A CompleteAnswer is a (complete-answer Set<RR> Set<RR> Set<RR>)
(struct: complete-answer
([rrs : (Setof RR)] [authorities : (Setof RR)] [additional : (Setof RR)])
#:transparent)
(define-type CompleteAnswer complete-answer)
(struct complete-answer (rrs authorities additional) #:transparent)
;; An RR is a (rr DomainName RRType RRClass Uint32 RData),
;; An RR is a (rr DomainName RRClass Uint32 RData),
;; representing a resource record.
(struct: rr ([name : DomainName]
[class : RRClass]
[ttl : Nonnegative-Integer]
[rdata : RData])
#:transparent)
(define-type RR rr)
(struct rr (name class ttl rdata) #:transparent)
;; An RData is one of
;; - a DomainName, for CNAME, MB, MD, MF, MG, MR, NS and PTR records
@ -181,30 +134,20 @@
;;
;; Many of these variants are obsolete in today's DNS database (marked
;; [O] above).
(struct: rdata ([type : RRType]) #:transparent)
(struct: rdata-domain rdata ([name : DomainName]) #:transparent)
(struct: rdata-ipv4 rdata ([address : IPv4]) #:transparent)
(struct: rdata-ipv6 rdata ([address : IPv6]) #:transparent)
(struct: rdata-hinfo rdata ([cpu : Bytes] [os : Bytes]) #:transparent)
(struct: rdata-minfo rdata ([rmailbx : DomainName] [emailbx : DomainName]) #:transparent)
(struct: rdata-mx rdata ([preference : Nonnegative-Integer] [exchange : DomainName]) #:transparent)
(struct: rdata-soa rdata ([mname : DomainName]
[rname : DomainName]
[serial : Nonnegative-Integer]
[refresh : Nonnegative-Integer]
[retry : Nonnegative-Integer]
[expire : Nonnegative-Integer]
[minimum : Nonnegative-Integer]) #:transparent)
(struct: rdata-wks rdata ([address : IPv4] [protocol : Byte] [bitmap : Bytes]) #:transparent)
(struct: rdata-srv rdata ([priority : Nonnegative-Integer]
[weight : Nonnegative-Integer]
[port : Nonnegative-Integer]
[target : DomainName]) #:transparent)
(struct: rdata-txt rdata ([strings : (Listof Bytes)]) #:transparent)
(struct: rdata-raw rdata ([body : Bytes]) #:transparent)
(define-type RData rdata)
(struct rdata (type) #:transparent)
(struct rdata-domain rdata (name) #:transparent)
(struct rdata-ipv4 rdata (address) #:transparent)
(struct rdata-ipv6 rdata (address) #:transparent)
(struct rdata-hinfo rdata (cpu os) #:transparent)
(struct rdata-minfo rdata (rmailbx emailbx) #:transparent)
(struct rdata-mx rdata (preference exchange) #:transparent)
(struct rdata-soa rdata (mname rname serial refresh retry expire minimum) #:transparent)
(struct rdata-wks rdata (address protocol bitmap) #:transparent)
(struct rdata-srv rdata (priority weight port target) #:transparent)
(struct rdata-txt rdata (strings) #:transparent)
(struct rdata-raw rdata (body) #:transparent)
(: rdata-type-pred : RRType -> (RData -> Boolean))
;; (: rdata-type-pred : RRType -> (RData -> Boolean))
(define ((rdata-type-pred t) d)
(eq? (rdata-type d) t))
@ -212,12 +155,8 @@
;; in the following define-mapping. It represents the type of an
;; RR. When used in an RR with an RData, the RRType and the RData
;; variant must correspond.
(define-type RRType (U 'a 'ns 'md 'mf 'cname 'soa 'mb 'mg
'mr 'null 'wks 'ptr 'hinfo 'minfo 'mx 'txt
'aaaa 'srv
Nonnegative-Integer))
(: type->value : RRType -> Nonnegative-Integer)
(: value->type : Nonnegative-Integer -> RRType)
;; (: type->value : RRType -> Nonnegative-Integer)
;; (: value->type : Nonnegative-Integer -> RRType)
(define-mapping type->value value->type
#:forward-default values
#:backward-default values
@ -243,9 +182,8 @@
;; A QueryType is a Symbol or Number (as given in the following
;; define-mapping) or an RRType. It specifies the kinds of records
;; being sought after in a DNS query.
(define-type QueryType (U RRType 'axfr 'mailb 'maila '*))
(: qtype->value : QueryType -> Nonnegative-Integer)
(: value->qtype : Nonnegative-Integer -> QueryType)
;; (: qtype->value : QueryType -> Nonnegative-Integer)
;; (: value->qtype : Nonnegative-Integer -> QueryType)
(define-mapping qtype->value value->qtype
#:forward-default type->value
#:backward-default value->type
@ -258,9 +196,8 @@
;; in the following define-mapping. It represents the "class" of DNS
;; records being discussed. All classes except 'in are obsolete in
;; today's DNS databases.
(define-type RRClass (U 'in 'cs 'ch 'hs Nonnegative-Integer))
(: class->value : RRClass -> Nonnegative-Integer)
(: value->class : Nonnegative-Integer -> RRClass)
;; (: class->value : RRClass -> Nonnegative-Integer)
;; (: value->class : Nonnegative-Integer -> RRClass)
(define-mapping class->value value->class
#:forward-default values
#:backward-default values
@ -272,48 +209,28 @@
;; A QueryClass is a Symbol or Number (as given in the following
;; define-mapping) or an RRClass. It specifies the "class" of records
;; being sought after in a DNS query.
(define-type QueryClass (U RRClass '*))
(: qclass->value : QueryClass -> Nonnegative-Integer)
(: value->qclass : Nonnegative-Integer -> QueryClass)
;; (: qclass->value : QueryClass -> Nonnegative-Integer)
;; (: value->qclass : Nonnegative-Integer -> QueryClass)
(define-mapping qclass->value value->qclass
#:forward-default class->value
#:backward-default value->class
(* 255))
;; ListOf<Bytes> -> ListOf<Bytes>
;; Converts the 7-bit ASCII bytes in the argument to lower-case
;; equivalents. Used to normalize case for domain-name comparisons.
(: downcase-labels : (Listof Bytes) -> (Listof Bytes))
(define (downcase-labels labels)
(for/list ([label labels])
(define b (make-bytes (bytes-length label)))
(for ([i (bytes-length label)])
(define v (bytes-ref label i))
(bytes-set! b i (if (<= 65 v 90) (+ 32 v) v)))
b))
;; ListOf<Bytes> -> DomainName
;; Replacement constructor for domain structs. Automatically downcases
;; labels appropriately.
(: make-domain : (Listof Bytes) -> DomainName)
(define (make-domain labels)
(domain labels (downcase-labels labels)))
(: domain-root? : DomainName -> Boolean)
;; (: domain-root? : DomainName -> Boolean)
(define (domain-root? d)
(null? (domain-labels d)))
(: domain-parent : DomainName -> (Option DomainName))
;; (: domain-parent : DomainName -> (Option DomainName))
(define (domain-parent d)
(and (pair? (domain-labels d))
(domain (cdr (domain-labels d))
(cdr (domain-downcased-labels d)))))
(: empty-complete-answer : -> CompleteAnswer)
;; (: empty-complete-answer : -> CompleteAnswer)
(define (empty-complete-answer)
(complete-answer (set) (set) (set)))
(: merge-answers : CompleteAnswer CompleteAnswer -> CompleteAnswer)
;; (: merge-answers : CompleteAnswer CompleteAnswer -> CompleteAnswer)
(define (merge-answers a1 a2)
(match-define (complete-answer n1 u1 d1) a1)
(match-define (complete-answer n2 u2 d2) a2)
@ -321,7 +238,7 @@
(set-union u1 u2)
(set-union d1 d2)))
(: extract-addresses : DomainName (Option CompleteAnswer) -> (Setof IPv4))
;; (: extract-addresses : DomainName (Option CompleteAnswer) -> (Setof IPv4))
(define (extract-addresses name ans)
(match ans
[#f ;; name-error/NXDOMAIN, so definitely no addresses.
@ -329,12 +246,12 @@
[(complete-answer ns us ds)
(define rrs (set->list (set-union ns us ds)))
(let loop ((names (list name))
(ips ((inst set IPv4)))
(seen ((inst set DomainName))))
(ips (set))
(seen (set)))
(if (null? names)
ips
(let* ((name (car names))
(records (filter (lambda: ([rr : RR]) (equal? name (rr-name rr))) rrs))
(records (filter (lambda (rr) (equal? name (rr-name rr))) rrs))
(data (map rr-rdata records)))
(if (set-member? seen name)
(loop (cdr names) ips seen)
@ -348,10 +265,10 @@
;; #t iff this question is being asked in order to supply answers
;; contributing to a parent context that's trying to answer exactly
;; this question.
(: question-cyclic? : Question -> Boolean)
;; (: question-cyclic? : Question -> Boolean)
(define (question-cyclic? q)
(match-define (question name type class parent) q)
(let: search : Boolean ((ancestor : QuestionContext parent))
(let search ((ancestor parent))
(match ancestor
[(subquestion (question (== name) (== type) (== class) _)) #t] ;; uh-oh! A cycle!
[(subquestion (question _ _ _ ancestor-parent)) (search ancestor-parent)] ;; recursive case
@ -363,10 +280,10 @@
;; from the outside world, then that's too glueless. See
;; http://cr.yp.to/djbdns/notes.html in the sections "Gluelessness"
;; and "Expiring glue".
(: question-too-glueless? : Question -> Boolean)
;; (: question-too-glueless? : Question -> Boolean)
(define (question-too-glueless? q)
(define count
(let: search : Integer ((q : Question q) (acc : Integer 0))
(let search ((q q) (acc 0))
(match-define (question _ _ _ parent) q)
(cond
[(ns-subq? parent) (search (subquestion-parent parent) (+ acc 1))]
@ -382,7 +299,7 @@
;; Question -> Boolean
;; #t iff this question is being asked in the context of some
;; excessively glueless subquestion.
(: question-restarted? : Question -> Boolean)
;; (: question-restarted? : Question -> Boolean)
(define (question-restarted? q)
(match-define (question name type class parent) q)
(let search ((ancestor parent))
@ -394,19 +311,19 @@
;; Question -> Question
;; Returns a question equivalent to q, but in a 'restart context, for
;; retracing from the roots in cases of excessive gluelessness.
(: restart-question : Question -> Question)
;; (: restart-question : Question -> Question)
(define (restart-question q)
(struct-copy question-repr q [context 'restart]))
(struct-copy question q [context 'restart]))
;; DomainName Question -> Question
;; Produces a new question with CNAME context.
(: cname-question : DomainName Question -> Question)
;; (: cname-question : DomainName Question -> Question)
(define (cname-question name q)
(match-define (question _ type class _) q)
(question name type class (cname-subq q)))
;; DomainName Question -> Question
;; Produces a new question with NS context.
(: ns-question : DomainName Question -> Question)
;; (: ns-question : DomainName Question -> Question)
(define (ns-question name q)
(question name 'a 'in (ns-subq q))) ;; TODO: 'aaaa ?

93
codec.rkt
View File

@ -1,4 +1,4 @@
#lang typed/racket/base
#lang racket/base
;; DNS wire-protocol codec.
;;
;;; Copyright 2010, 2011, 2012, 2013 Tony Garnock-Jones <tonyg@ccs.neu.edu>
@ -19,17 +19,9 @@
;;; along with marketplace-dns. If not, see
;;; <http://www.gnu.org/licenses/>.
(provide Opcode
ResponseCode
value->query-opcode query-opcode->value
(provide value->query-opcode query-opcode->value
value->query-response-code query-response-code->value
DNSMessage
Direction
Authoritativeness
Truncatedness
RecursionDesired
RecursionAvailable
(struct-out dns-message)
packet->dns-message
@ -50,9 +42,8 @@
;; An Opcode is a Symbol or a Number, one of the possibilities given
;; in the following define-mapping. It represents a DNS message
;; operation; see the RFC for details.
(define-type Opcode (U 'query 'iquery 'status Nonnegative-Integer))
(: value->query-opcode : Nonnegative-Integer -> Opcode)
(: query-opcode->value : Opcode -> Nonnegative-Integer)
;; (: value->query-opcode : Nonnegative-Integer -> Opcode)
;; (: query-opcode->value : Opcode -> Nonnegative-Integer)
(define-mapping value->query-opcode query-opcode->value
#:forward-default values
#:backward-default values
@ -63,11 +54,8 @@
;; A ResponseCode is a Symbol or a Number, one of the possibilities
;; given in the following define-mapping. It represents the outcome of
;; a DNS query.
(define-type ResponseCode (U 'no-error 'format-error 'server-failure
'name-error 'not-implemented 'refused
Nonnegative-Integer))
(: value->query-response-code : Nonnegative-Integer -> ResponseCode)
(: query-response-code->value : ResponseCode -> Nonnegative-Integer)
;; (: value->query-response-code : Nonnegative-Integer -> ResponseCode)
;; (: query-response-code->value : ResponseCode -> Nonnegative-Integer)
(define-mapping value->query-response-code query-response-code->value
(0 no-error)
(1 format-error)
@ -83,25 +71,24 @@
;;
;; Interpreted as either a DNS request or reply, depending on the
;; Direction.
(struct: dns-message ([id : Nonnegative-Integer]
[direction : Direction]
[opcode : Opcode]
[authoritative : Authoritativeness]
[truncated : Truncatedness]
[recursion-desired : RecursionDesired]
[recursion-available : RecursionAvailable]
[response-code : ResponseCode]
[questions : (Listof Question)]
[answers : (Listof RR)]
[authorities : (Listof RR)]
[additional : (Listof RR)])
#:transparent)
(define-type DNSMessage dns-message)
(define-type Direction (U 'request 'response))
(define-type Authoritativeness (U 'non-authoritative 'authoritative))
(define-type Truncatedness (U 'not-truncated 'truncated))
(define-type RecursionDesired (U 'no-recursion-desired 'recursion-desired))
(define-type RecursionAvailable (U 'no-recursion-available 'recursion-available))
(struct dns-message (id
direction
opcode
authoritative
truncated
recursion-desired
recursion-available
response-code
questions
answers
authorities
additional)
#:transparent)
;; (define-type Direction (U 'request 'response))
;; (define-type Authoritativeness (U 'non-authoritative 'authoritative))
;; (define-type Truncatedness (U 'not-truncated 'truncated))
;; (define-type RecursionDesired (U 'no-recursion-desired 'recursion-desired))
;; (define-type RecursionAvailable (U 'no-recursion-available 'recursion-available))
;; Bit-syntax type for counted repeats of a value.
;; Example: Length-prefixed list of 32-bit unsigned words:
@ -115,7 +102,7 @@
;; here, but I can't find a way of expressing the types
;; required while making that work. This way, we avoid needing
;; to mention the type of the result of calls to ks.
(: loop : Integer (Listof Type) BitString -> (Values (Option (Listof Type)) BitString))
;; (: loop : Integer (Listof Type) BitString -> (Values (Option (Listof Type)) BitString))
(define (loop count acc input)
(cond
((positive? count) (bit-string-case input
@ -158,7 +145,7 @@
(else
(kf))))
((_ #f vs Type option ...)
(let: loop : BitString ((vs : (Listof Type) vs))
(let loop ((vs vs))
(cond
((pair? vs) (bit-string ((car vs) :: option ...)
((loop (cdr vs)) :: binary)))
@ -202,7 +189,7 @@
;; +--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+--+
;; </rfc1035>
(: packet->dns-message : BitString -> DNSMessage)
;; (: packet->dns-message : BitString -> DNSMessage)
;; Parse an encoded DNS message packet into the corresponding Racket
;; structure. Raises an exception on failure.
(define (packet->dns-message packet)
@ -232,7 +219,7 @@
(value->query-response-code rcode)
q-section a-section auth-section additional-section))))
(: dns-message->packet : DNSMessage -> Bytes)
;; (: dns-message->packet : DNSMessage -> Bytes)
;; Render a Racket structured DNS message using the DNS binary encoding.
(define (dns-message->packet m)
(bit-string->bytes
@ -288,14 +275,14 @@
((_ #f val)
(encode-domain-name val))))
(: encode-domain-name : DomainName -> BitString)
;; (: encode-domain-name : DomainName -> BitString)
(define (encode-domain-name name)
(define labels (domain-labels name))
(bit-string (labels :: (t:listof Bytes (t:pascal-string "Label" 64)))
(0 :: integer bytes 1))) ;; end of list of labels!
(: parse-domain-name :
BitString BitString (Listof Natural) -> (Values (Listof Bytes) BitString))
;; (: parse-domain-name :
;; BitString BitString (Listof Natural) -> (Values (Listof Bytes) BitString))
;; PRECONDITION: input never empty
;; INVARIANT: pointers-followed contains every "jump target" we have
;; jumped to so far during decoding of this domain-name, in order to
@ -337,7 +324,7 @@
((_ #f val)
(t:pascal-string #f val "Character-string" 256))
((_ #f val string-kind length-limit)
(let: ([s : Bytes val])
(let ([s val])
(let ((len (bytes-length s)))
(when (>= len length-limit)
(error 't:pascal-string "~s too long: ~v" string-kind s))
@ -377,10 +364,10 @@
#f)
tail))))
((_ #f val)
(let: ([q : Question val])
(bit-string ((question-repr-name q) :: (t:domain-name))
((qtype->value (question-repr-type q)) :: bits 16)
((qclass->value (question-repr-class q)) :: bits 16))))))
(let ([q val])
(bit-string ((question-name q) :: (t:domain-name))
((qtype->value (question-type q)) :: bits 16)
((qclass->value (question-class q)) :: bits 16))))))
;; <rfc1035>
;; All RRs have the same top level format shown below:
@ -429,7 +416,7 @@
tail)))
(else (kf)))))
((_ #f val)
(let: ([rr : RR val])
(let ([rr val])
(let ((encoded-rdata (encode-rdata (rr-rdata rr))))
(bit-string ((rr-name rr) :: (t:domain-name))
((type->value (rdata-type (rr-rdata rr))) :: bits 16)
@ -438,7 +425,7 @@
((quotient (bit-string-length encoded-rdata) 8) :: bits 16)
(encoded-rdata :: binary)))))))
(: decode-rdata : BitString RRType BitString -> RData)
;; (: decode-rdata : BitString RRType BitString -> RData)
;; Decode RData according to the RRType. Takes the whole packet for
;; the same reason as t:rr does.
(define (decode-rdata whole-packet type rdata)
@ -487,7 +474,7 @@
(rdata-srv type priority weight port target))))
(else (rdata-raw type (bit-string->bytes rdata)))))
(: encode-rdata : RData -> BitString)
;; (: encode-rdata : RData -> BitString)
;; Encode RData according to its RRType.
(define (encode-rdata rdata)
(match rdata
@ -519,5 +506,5 @@
[(rdata-raw _ bs) bs]))
;; UInt32
(: max-ttl : Nonnegative-Integer)
;; (: max-ttl : Nonnegative-Integer)
(define max-ttl #xffffffff)

42
driver.rkt
View File

@ -1,4 +1,4 @@
#lang typed/racket/base
#lang racket/base
;; DNS server using os-big-bang.rkt and os-udp.rkt.
;;
;;; Copyright 2010, 2011, 2012, 2013 Tony Garnock-Jones <tonyg@ccs.neu.edu>
@ -28,7 +28,7 @@
(require "codec.rkt")
(require "zonedb.rkt")
(require "resolver.rkt")
(require marketplace/sugar-typed)
(require marketplace/sugar)
(require marketplace/support/spy)
(require marketplace/drivers/udp)
(require "tk-dns.rkt")
@ -46,7 +46,7 @@
;; determines subzones based on the RRs it is configured with at
;; startup.
(: start-server : Nonnegative-Integer RR (Listof RR) -> Void)
;; (: start-server : Nonnegative-Integer RR (Listof RR) -> Void)
;; Starts a server that will answer questions received on the given
;; UDP port based on the RRs it is given and the zone origin specified
;; in the soa-rr given.
@ -58,26 +58,26 @@
(display ";; Ready.\n")
(ground-vm: ((inst udp-driver Void))
((inst generic-spy Void) 'UDP)
(spawn-vm: : Void
(spawn: #:parent : Void #:child : Void (dns-spy))
(spawn: #:parent : Void #:child : Void (dns-read-driver local-addr))
(spawn: #:parent : Void #:child : Void (dns-write-driver local-addr))
(subscriber: Void (bad-dns-packet-pattern (wild) (wild) (wild) (wild))
(on-message [p (begin (log-error (pretty-format p)) '())]))
(subscriber: Void (dns-request-pattern (wild) (wild) (wild))
(on-message [(? dns-request? r)
(let ((reply (handle-request soa-rr zone r)))
(when reply (send-message reply)))])))))
(ground-vm (udp-driver)
(generic-spy 'UDP)
(spawn-vm
(spawn (dns-spy))
(spawn (dns-read-driver local-addr))
(spawn (dns-write-driver local-addr))
(subscriber (bad-dns-packet (wild) (wild) (wild) (wild))
(on-message [p (begin (log-error (pretty-format p)) '())]))
(subscriber (dns-request (wild) (wild) (wild))
(on-message [(? dns-request? r)
(let ((reply (handle-request soa-rr zone r)))
(when reply (send-message reply)))])))))
(define-type ReplyMaker (DomainName Boolean (Setof RR) (Setof RR) (Setof RR) -> DNSMessage))
;; (define-type ReplyMaker (DomainName Boolean (Setof RR) (Setof RR) (Setof RR) -> DNSMessage))
(: handle-request : RR CompiledZone DNSRequest -> (Option DNSReply))
;; (: handle-request : RR CompiledZone DNSRequest -> (Option DNSReply))
(define (handle-request soa-rr zone request)
(match-define (dns-request request-message request-source request-sink) request)
(: make-reply : ReplyMaker)
;; (: make-reply : ReplyMaker)
(define (make-reply name send-name-error? answers authorities additional)
(dns-message (dns-message-id request-message)
'response
@ -92,7 +92,7 @@
(rr-set->list authorities)
(rr-set->list additional)))
(: answer-question : Question ReplyMaker -> DNSMessage)
;; (: answer-question : Question ReplyMaker -> DNSMessage)
(define (answer-question q make-reply)
;; Notice that we claim to be authoritative for our configured
;; zone. If we ever answer name-error, that means there are no RRs
@ -110,7 +110,7 @@
;; here. Reexamine the rules for doing so.
(match-define (question qname qtype qclass #f) q)
(: expand-cnames : (Listof DomainName) CompleteAnswer -> DNSMessage)
;; (: expand-cnames : (Listof DomainName) CompleteAnswer -> DNSMessage)
(define (expand-cnames worklist ans)
(match worklist
['()
@ -120,7 +120,7 @@
(define a (resolve-from-zone (cname-question next-cname q) zone soa-rr (set)))
(incorporate-answer a rest ans)]))
(: incorporate-answer : Answer (Listof DomainName) CompleteAnswer -> DNSMessage)
;; (: incorporate-answer : Answer (Listof DomainName) CompleteAnswer -> DNSMessage)
(define (incorporate-answer this-answer worklist ans)
(match this-answer
[(partial-answer new-info more-cnames)

2
mapping.rkt
View File

@ -1,4 +1,4 @@
#lang typed/racket/base
#lang racket/base
;; Macros for defining weak and extensible mappings between sets of values
;;
;;; Copyright 2010, 2011, 2012, 2013 Tony Garnock-Jones <tonyg@ccs.neu.edu>

151
network-query.rkt
View File

@ -1,4 +1,4 @@
#lang typed/racket/base
#lang racket/base
;;
;;; Copyright 2010, 2011, 2012, 2013 Tony Garnock-Jones <tonyg@ccs.neu.edu>
;;;
@ -23,17 +23,13 @@
(require "api.rkt")
(require "codec.rkt")
(require "zonedb.rkt")
(require marketplace/sugar-typed)
(require marketplace/sugar)
(require marketplace/drivers/udp)
(require marketplace/drivers/timer)
(require marketplace/support/pseudo-substruct)
(require "tk-dns.rkt")
(require (rename-in marketplace/tr-struct-copy [tr-struct-copy struct-copy])) ;; PR13149
(provide network-query
(struct-out network-reply-repr)
NetworkReply network-reply network-reply?
NetworkReplyPattern network-reply-pattern network-reply-pattern?)
(struct-out network-reply))
;; DJB's rules for handling DNS responses. Some of these are handled
;; here (specifically, rules 2 through 5, in the action of
@ -130,45 +126,32 @@
;; A NetworkRequest is a (network-request UdpAddress Question
;; DomainName NEListOf<DomainName> UniqueID) representing the
;; parameters used to start and process a network query.
(struct: network-request ([client-socket : UdpAddress]
[question : Question]
[zone-origin : DomainName]
[server-names : (Listof DomainName)]
[unique-id : Any])
#:transparent)
(define-type NetworkRequest network-request)
(struct network-request (client-socket question zone-origin server-names unique-id) #:transparent)
;; A NetworkReply is a (network-reply UniqueID Maybe<CompleteAnswer>)
;; representing the final result of a network query.
(struct: (TId TAnswer)
network-reply-repr
([unique-id : TId] [answer : TAnswer]) #:transparent)
(pseudo-substruct: (network-reply-repr Any (Option CompleteAnswer))
NetworkReply network-reply network-reply?)
(pseudo-substruct: (network-reply-repr (U Wild Any) (U Wild (Option CompleteAnswer)))
NetworkReplyPattern network-reply-pattern network-reply-pattern?)
(struct network-reply (unique-id answer) #:transparent)
;; A NetworkQueryState is a (network-query-state NetworkRequest
;; Integer Map<DomainName,ListOf<UdpAddress>> ListOf<UdpAddress>
;; Maybe<DomainName> ListOf<DomainName>), representing an in-progress
;; DNS network query.
(struct: network-query-state ([request : NetworkRequest]
[timeout : (Option Natural)]
[known-addresses : (HashTable DomainName (Listof UdpAddress))]
[remaining-addresses : (Listof UdpAddress)]
[current-name : (Option DomainName)]
[remaining-names : (Listof DomainName)])
#:transparent)
(define-type NetworkQueryState network-query-state)
(struct network-query-state (request
timeout
known-addresses
remaining-addresses
current-name
remaining-names)
#:transparent)
(: next-timeout : Natural -> (Option Natural))
;; (: next-timeout : Natural -> (Option Natural))
(define (next-timeout timeout)
(cond
[(equal? timeout 3) 11]
[(equal? timeout 11) 45]
[else #f]))
(: make-dns-query-message : Question Nonnegative-Integer -> DNSMessage)
;; (: make-dns-query-message : Question Nonnegative-Integer -> DNSMessage)
(define (make-dns-query-message q query-id)
(dns-message query-id
'request
@ -183,9 +166,9 @@
'()
'()))
(define-type CheckedAnswer (U (Option CompleteAnswer) 'bad-answer 'lame-delegation))
;; (define-type CheckedAnswer (U (Option CompleteAnswer) 'bad-answer 'lame-delegation))
(: filter-dns-reply : Question DNSMessage DomainName -> CheckedAnswer)
;; (: filter-dns-reply : Question DNSMessage DomainName -> CheckedAnswer)
;; Filters RRs from the answer, authorities, and additional sections
;; of the passed-in `message`, returning the set of RRs surviving the
;; filter. RRs are only accepted if their `rr-name` falls in the
@ -200,25 +183,24 @@
(define (filter-dns-reply q message zone-origin)
(case (dns-message-response-code message)
[(no-error)
(: f : (Listof RR) -> (Setof RR))
;; (: f : (Listof RR) -> (Setof RR))
(define (f l)
(list->set (filter (lambda: ([claim-rr : RR])
(in-bailiwick? (rr-name claim-rr) zone-origin)) l)))
(list->set (filter (lambda (claim-rr) (in-bailiwick? (rr-name claim-rr) zone-origin)) l)))
;; Here's where we do the "lame referral" check. This code is
;; nice and simple (though wrong) without it. Ho hum.
(define answers (f (dns-message-answers message)))
(define unfiltered-authorities (dns-message-authorities message))
(define non-subzone-ns-rrs ;; all NS authorities not for a STRICT subzone of our zone-origin
(filter (lambda: ([rr : RR]) (and (eqv? (rdata-type (rr-rdata rr)) 'ns)
(or (equal? (rr-name rr) zone-origin)
(not (in-bailiwick? (rr-name rr) zone-origin)))))
(filter (lambda (rr) (and (eqv? (rdata-type (rr-rdata rr)) 'ns)
(or (equal? (rr-name rr) zone-origin)
(not (in-bailiwick? (rr-name rr) zone-origin)))))
unfiltered-authorities))
(define authorities (f unfiltered-authorities))
(define answers-to-q ;; answers specifically to the question we asked
(set-filter (lambda: ([rr : RR]) (equal? (rr-name rr) (question-repr-name q))) answers))
(set-filter (lambda (rr) (equal? (rr-name rr) (question-name q))) answers))
(define lame?
(and (set-empty? (filter-by-type answers-to-q 'cname))
(set-empty? (filter-rrs answers-to-q (question-repr-type q) (question-repr-class q)))
(set-empty? (filter-rrs answers-to-q (question-type q) (question-class q)))
(set-empty? (filter-by-type authorities 'soa))
(not (null? non-subzone-ns-rrs))))
(if lame?
@ -233,31 +215,29 @@
(dns-message-questions message)))
'bad-answer]))
(: ip->host-name : IPv4 -> String)
;; (: ip->host-name : IPv4 -> String)
(define (ip->host-name ip-address)
(match-define (vector a b c d) ip-address)
(format "~a.~a.~a.~a" a b c d))
(: make-dns-address : IPv4 -> UdpAddress)
;; (: make-dns-address : IPv4 -> UdpAddress)
(define (make-dns-address ip-address)
(udp-remote-address (ip->host-name ip-address) 53))
(: network-query : (All (ParentState)
UdpAddress Question DomainName (Listof DomainName) Any ->
(Action ParentState)))
;; (: network-query : (All (ParentState)
;; UdpAddress Question DomainName (Listof DomainName) Any ->
;; (Action ParentState)))
(define (network-query s q zone-origin server-names unique-id)
(name-process (list 'network-query q)
(spawn: #:parent : ParentState
#:child : NetworkQueryState
(try-next-server
(network-query-state (network-request s q zone-origin server-names unique-id)
first-timeout
(ann #hash() (HashTable DomainName (Listof UdpAddress)))
'()
#f
server-names)))))
(spawn (try-next-server
(network-query-state (network-request s q zone-origin server-names unique-id)
first-timeout
#hash()
'()
#f
server-names)))))
(: try-next-server : NetworkQueryState -> (Transition NetworkQueryState))
;; (: try-next-server : NetworkQueryState -> (Transition NetworkQueryState))
(define (try-next-server w)
(define timeout (network-query-state-timeout w))
(if (not timeout)
@ -280,31 +260,31 @@
[current-name current-name]
[remaining-names remaining-names]))
(let ((subq (ns-question current-name (network-request-question req))))
(transition: (struct-copy network-query-state w
[current-name current-name]
[remaining-names remaining-names]) : NetworkQueryState
(transition (struct-copy network-query-state w
[current-name current-name]
[remaining-names remaining-names])
(send-message subq)
(let-fresh (subq-id)
(name-endpoint subq-id
(subscriber: NetworkQueryState (answered-question-pattern subq (wild))
(subscriber (answered-question subq (wild))
(match-state w
(on-message
[(answered-question (== subq) ans)
(let ((ips (map make-dns-address
(set->list (extract-addresses current-name ans)))))
(sequence-actions
(try-next-server (struct-copy network-query-state w
[known-addresses (hash-set known-addresses
current-name
ips)]
[remaining-addresses ips]))
(delete-endpoint subq-id)))]))))))))]
(try-next-server (struct-copy network-query-state w
[known-addresses (hash-set known-addresses
current-name
ips)]
[remaining-addresses ips]))
(delete-endpoint subq-id)))]))))))))]
[(network-query-state req _ _ (cons current-ip remaining-ips) _ _)
(define rpc-id (gensym 'network-query/allocate-query-id))
(transition: w : NetworkQueryState
(transition w
(send-message `(request ,rpc-id allocate-query-id))
(name-endpoint rpc-id
(subscriber: NetworkQueryState `(reply ,rpc-id ,(wild))
(subscriber `(reply ,rpc-id ,(wild))
(match-state w
(on-message
[`(reply ,(== rpc-id) ,(? exact-nonnegative-integer? id))
@ -313,10 +293,10 @@
id
timeout
current-ip)
(delete-endpoint rpc-id))])))))])))
(delete-endpoint rpc-id))])))))])))
(: on-answer : NetworkQueryState CheckedAnswer (Option UdpAddress)
-> (Transition NetworkQueryState))
;; (: on-answer : NetworkQueryState CheckedAnswer (Option UdpAddress)
;; -> (Transition NetworkQueryState))
(define (on-answer w ans server-ip)
(match ans
['bad-answer ;; can come from filter-dns-reply
@ -334,17 +314,16 @@
(struct-copy network-query-state w
[known-addresses (hash-update known-addresses
current-name
(lambda: ([addrs : (Listof
UdpAddress)])
(lambda (addrs)
(remove server-ip addrs)))])
w))]
[(and (or (? complete-answer?) #f) ans)
(transition: w : NetworkQueryState
(transition w
(send-message (network-reply (network-request-unique-id (network-query-state-request w))
ans)))]))
(: send-request : NetworkQueryState Nonnegative-Integer Natural UdpAddress
-> (Transition NetworkQueryState))
;; (: send-request : NetworkQueryState Nonnegative-Integer Natural UdpAddress
;; -> (Transition NetworkQueryState))
(define (send-request w query-id timeout server-ip)
(match-define (network-request s q zone-origin _ _) (network-query-state-request w))
(define query (make-dns-query-message q query-id))
@ -355,12 +334,12 @@
q query-id
zone-origin server-ip
timeout))
(transition: w : NetworkQueryState
(transition w
(send-message (dns-request query s server-ip))
(send-message (set-timer timeout-id (* timeout 1000) 'relative))
;; TODO: Restore this to a "join" when proper pattern-unions are implemented
(name-endpoint timeout-id
(subscriber: NetworkQueryState (timer-expired-pattern timeout-id (wild))
(subscriber (timer-expired timeout-id (wild))
(match-state w
(on-message
[(timer-expired (== timeout-id) _)
@ -370,11 +349,11 @@
zone-origin server-ip
timeout))
(sequence-actions (try-next-server w)
(delete-endpoint timeout-id)
(delete-endpoint reply-wait-id)
(send-message (list 'release-query-id query-id))))]))))
(delete-endpoint timeout-id)
(delete-endpoint reply-wait-id)
(send-message (list 'release-query-id query-id))))]))))
(name-endpoint reply-wait-id
(subscriber: NetworkQueryState (dns-reply-pattern (wild) (wild) s)
(subscriber (dns-reply (wild) (wild) s)
(match-state w
(on-message
[(dns-reply reply-message source (== s))
@ -389,10 +368,10 @@
(dns-message-authorities reply-message)
(dns-message-additional reply-message)))
(if (not (= (dns-message-id reply-message) (dns-message-id query)))
(transition: w : NetworkQueryState)
(transition w)
(sequence-actions (on-answer w
(filter-dns-reply q reply-message zone-origin)
server-ip)
(delete-endpoint timeout-id)
(delete-endpoint reply-wait-id)
(send-message (list 'release-query-id query-id)))))]))))))
(delete-endpoint timeout-id)
(delete-endpoint reply-wait-id)
(send-message (list 'release-query-id query-id)))))]))))))

230
proxy.rkt
View File

@ -1,4 +1,4 @@
#lang typed/racket/base
#lang racket/base
;; DNS proxy using os-big-bang.rkt and os-udp.rkt.
;;
;;; Copyright 2010, 2011, 2012, 2013 Tony Garnock-Jones <tonyg@ccs.neu.edu>
@ -28,7 +28,7 @@
(require "zonedb.rkt")
(require "network-query.rkt")
(require "resolver.rkt")
(require marketplace/sugar-typed)
(require marketplace/sugar)
(require marketplace/support/spy)
(require marketplace/drivers/timer)
(require marketplace/drivers/udp)
@ -40,70 +40,59 @@
;; searches from. Performs recursive queries.
;; For discarding retransmitted requests that we're still working on.
(struct: active-request ([source : UdpAddress] [id : Natural]) #:transparent)
(define-type ActiveRequest active-request)
(struct active-request (source id) #:transparent)
(: start-proxy : Natural CompiledZone CompiledZone -> Void)
;; (: start-proxy : Natural CompiledZone CompiledZone -> Void)
(define (start-proxy port-number zone roots-only)
(define server-addr (udp-listener port-number))
(define client-addr (udp-handle 'dns-client))
(log-info "Ready.")
(ground-vm:
((inst generic-spy Void) 'UDP)
((inst udp-driver Void))
((inst timer-driver Void))
(spawn-vm: : Void
#:debug-name 'dns-vm
(name-process 'dns-spy (spawn: #:parent : Void #:child : Void (dns-spy)))
((inst timer-relay Void) 'timer-relay:dns)
(name-process 'query-id-allocator (spawn: #:parent : Void #:child : (Setof Natural)
(query-id-allocator)))
(name-process 'server-dns-reader (spawn: #:parent : Void #:child : Void
(dns-read-driver server-addr)))
(name-process 'server-dns-writer (spawn: #:parent : Void #:child : Void
(dns-write-driver server-addr)))
(name-process 'client-dns-reader (spawn: #:parent : Void #:child : Void
(dns-read-driver client-addr)))
(name-process 'client-dns-writer (spawn: #:parent : Void #:child : Void
(dns-write-driver client-addr)))
(name-process 'packet-dispatcher (spawn: #:parent : Void
#:child : (Setof ActiveRequest)
(packet-dispatcher server-addr)))
(name-process 'question-dispatcher (spawn: #:parent : Void
#:child : CompiledZone
(question-dispatcher zone
roots-only
client-addr))))))
(ground-vm
(generic-spy 'UDP)
(udp-driver)
(timer-driver)
(spawn-vm #:debug-name 'dns-vm
(name-process 'dns-spy (spawn (dns-spy)))
(timer-relay 'timer-relay:dns)
(name-process 'query-id-allocator (spawn (query-id-allocator)))
(name-process 'server-dns-reader (spawn (dns-read-driver server-addr)))
(name-process 'server-dns-writer (spawn (dns-write-driver server-addr)))
(name-process 'client-dns-reader (spawn (dns-read-driver client-addr)))
(name-process 'client-dns-writer (spawn (dns-write-driver client-addr)))
(name-process 'packet-dispatcher (spawn (packet-dispatcher server-addr)))
(name-process 'question-dispatcher (spawn (question-dispatcher zone
roots-only
client-addr))))))
(: query-id-allocator : -> (Transition (Setof Natural)))
;; (: query-id-allocator : -> (Transition (Setof Natural)))
(define (query-id-allocator)
;; TODO: track how many are allocated and throttle requests if too
;; many are in flight
(transition: ((inst set Natural)) : (Setof Natural) ;; all active query IDs
(subscriber: (Setof Natural) `(request ,(wild) allocate-query-id)
(transition (set) ;; all active query IDs
(subscriber `(request ,(wild) allocate-query-id)
(match-state allocated
(on-message
[`(request ,reply-addr allocate-query-id)
(let: recheck : (Transition (Setof Natural)) ()
(define n (random 65536))
(if (set-member? allocated n)
(recheck)
(transition: (set-add allocated n) : (Setof Natural)
(send-message `(reply ,reply-addr ,n)))))])))
(subscriber: (Setof Natural) `(release-query-id ,(wild))
(let recheck ()
(define n (random 65536))
(if (set-member? allocated n)
(recheck)
(transition (set-add allocated n)
(send-message `(reply ,reply-addr ,n)))))])))
(subscriber `(release-query-id ,(wild))
(match-state allocated
(on-message
[`(release-query-id ,(? exact-nonnegative-integer? n))
(transition: (set-remove allocated n) : (Setof Natural))])))))
(transition (set-remove allocated n))])))))
(: packet-dispatcher : UdpAddress -> (Transition (Setof ActiveRequest)))
;; (: packet-dispatcher : UdpAddress -> (Transition (Setof ActiveRequest)))
(define (packet-dispatcher s)
(transition: ((inst set ActiveRequest)) : (Setof ActiveRequest)
(subscriber: (Setof ActiveRequest) (bad-dns-packet-pattern (wild) (wild) (wild) (wild))
(transition (set)
(subscriber (bad-dns-packet (wild) (wild) (wild) (wild))
(on-message [p (begin (log-error (pretty-format p)) '())]))
(subscriber: (Setof ActiveRequest) (dns-request-pattern (wild) (wild) s)
(subscriber (dns-request (wild) (wild) s)
(match-state old-active-requests
(on-message
[(and r (dns-request m source (== s)))
@ -112,23 +101,22 @@
;; TODO: when we have presence/error-handling, remove req-id
;; from active requests once request-handler pseudothread exits.
(if (set-member? old-active-requests req-id)
(transition: old-active-requests : (Setof ActiveRequest))
(transition old-active-requests)
;; ^ ignore retransmitted duplicates
(transition: (set-add old-active-requests req-id) : (Setof ActiveRequest)
(transition (set-add old-active-requests req-id)
(name-process (list 'packet-relay req-id)
(spawn: #:parent : (Setof ActiveRequest)
#:child : Void (packet-relay req-id r))))))])))
(subscriber: (Setof ActiveRequest) (dns-reply-pattern (wild) s (wild))
(spawn (packet-relay req-id r))))))])))
(subscriber (dns-reply (wild) s (wild))
(match-state old-active-requests
(on-message
[(and r (dns-reply m (== s) sink))
(let ((req-id (active-request sink (dns-message-id m))))
(transition: (set-remove old-active-requests req-id) : (Setof ActiveRequest)))])))))
(transition (set-remove old-active-requests req-id)))])))))
(: packet-relay : ActiveRequest DNSRequest -> (Transition Void))
;; (: packet-relay : ActiveRequest DNSRequest -> (Transition Void))
(define (packet-relay req-id request)
(match-define (dns-request request-message request-source request-sink) request)
(: answer->reply : (Option Question) (Option CompleteAnswer) -> DNSReply)
;; (: answer->reply : (Option Question) (Option CompleteAnswer) -> DNSReply)
(define (answer->reply q a)
(define-values (response-code ns us ds)
(match a
@ -165,7 +153,7 @@
(send-message original-question)
(let-fresh (wait-id)
(name-endpoint wait-id
(subscriber: Void (answered-question-pattern original-question (wild))
(subscriber (answered-question original-question (wild))
(on-message
[(answered-question (== original-question) answer)
(begin (log-debug (format "Final answer to ~v with query id ~v is ~v"
@ -175,14 +163,14 @@
(list (delete-endpoint wait-id)
(send-message (answer->reply original-question answer))))])))))]))
(: glueless-question-handler : CompiledZone Question UdpAddress -> (Transition Void))
;; (: glueless-question-handler : CompiledZone Question UdpAddress -> (Transition Void))
(define (glueless-question-handler roots-only-zone q client-sock)
;; Restart q, an overly-glueless question, from the roots.
(define restarted-question (restart-question q))
(transition/no-state
(let-fresh (relay)
(name-endpoint relay
(subscriber: Void (answered-question-pattern restarted-question (wild))
(subscriber (answered-question restarted-question (wild))
(on-message
[(answered-question (== restarted-question) ans)
;; We got the answer to our restarted question; now transform
@ -191,23 +179,21 @@
(list (delete-endpoint relay)
(send-message (answered-question q ans)))]))))
(name-process (list 'glueless-question-handler-inner restarted-question)
(spawn: #:parent : Void
#:child : QHState
(question-handler roots-only-zone restarted-question client-sock)))))
(spawn (question-handler roots-only-zone restarted-question client-sock)))))
(: question-dispatcher : CompiledZone CompiledZone UdpAddress -> (Transition CompiledZone))
;; (: question-dispatcher : CompiledZone CompiledZone UdpAddress -> (Transition CompiledZone))
(define (question-dispatcher seed-zone roots-only client-sock)
(: transition-and-set-timers : CompiledZone (Setof (Pairof DomainName Real))
-> (Transition CompiledZone))
;; (: transition-and-set-timers : CompiledZone (Setof (Pairof DomainName Real))
;; -> (Transition CompiledZone))
(define (transition-and-set-timers new-zone timers)
(transition: new-zone : CompiledZone
(for/list: : (Listof (Action CompiledZone)) ([timerspec timers])
(transition new-zone
(for/list ([timerspec timers])
(match-define (cons name ttl) timerspec)
(send-message (set-timer (list 'check-dns-expiry name) (* ttl 1000) 'relative)))))
(define-values (cleaned-seed-zone initial-timers) (zone-expire seed-zone))
(sequence-actions (transition-and-set-timers cleaned-seed-zone initial-timers)
;; TODO: consider deduping questions here too?
(subscriber: CompiledZone `(debug-dump)
(subscriber `(debug-dump)
(match-state zone
(on-message
[`(debug-dump)
@ -222,9 +208,9 @@
(display "----------------------------------------------------------------------\n")
(display (seconds->date (current-seconds)))
(newline)
(for: ([name (in-hash-keys zone)])
(for ([name (in-hash-keys zone)])
(define rrmap (hash-ref zone name))
(for: ([rr (in-hash-keys rrmap)])
(for ([rr (in-hash-keys rrmap)])
(define expiry (hash-ref rrmap rr))
(write (list rr expiry))
(newline)))
@ -239,12 +225,12 @@
;; (pretty-write current-ground-transition))
;; #:mode 'text
;; #:exists 'append)
(transition: zone : CompiledZone))])))
(subscriber: CompiledZone (question-pattern (wild) (wild) (wild) (wild))
(transition zone))])))
(subscriber (question (wild) (wild) (wild) (wild))
(match-state zone
(on-message
[(? question? q)
(transition: zone : CompiledZone
(transition zone
(cond
[(question-cyclic? q)
(log-warning (format "Cyclic question ~v" q))
@ -252,49 +238,37 @@
[(question-too-glueless? q)
(log-warning (format "Overly-glueless question ~v" q))
(name-process (list 'glueless-question-handler-outer q)
(spawn: #:parent : CompiledZone
#:child : Void
(glueless-question-handler roots-only q client-sock)))]
(spawn (glueless-question-handler roots-only q client-sock)))]
[else
(name-process (list 'question-handler q)
(spawn: #:parent : CompiledZone
#:child : QHState
(question-handler zone q client-sock)))]))])))
(subscriber: CompiledZone (network-reply-pattern (wild) (wild))
(spawn (question-handler zone q client-sock)))]))])))
(subscriber (network-reply (wild) (wild))
(match-state zone
(on-message
[(network-reply _ answer)
(let-values (((new-zone timers) (incorporate-complete-answer answer zone #t)))
(transition-and-set-timers new-zone timers))])))
(subscriber: CompiledZone (timer-expired-pattern (list 'check-dns-expiry (wild)) (wild))
(subscriber (timer-expired (list 'check-dns-expiry (wild)) (wild))
(match-state zone
(on-message
[(timer-expired (list 'check-dns-expiry (? domain? name)) (? number? now-msec))
(transition: (zone-expire-name zone name (/ now-msec 1000.0)) : CompiledZone)])))))
(transition (zone-expire-name zone name (/ now-msec 1000.0)))])))))
(struct: question-state ([zone : CompiledZone]
[q : Question]
[client-sock : UdpAddress]
[nameservers-tried : (Setof DomainName)]
[retry-count : Natural]) #:transparent)
(define-type QuestionState question-state)
(struct question-state (zone q client-sock nameservers-tried retry-count) #:transparent)
(struct: expanding-cnames ([q : Question]
[accumulator : CompleteAnswer]
[remaining-count : Integer]) #:transparent)
(define-type ExpandingCNAMEs expanding-cnames)
(struct expanding-cnames (q accumulator remaining-count) #:transparent)
(define-type QHState (U QuestionState ExpandingCNAMEs))
;; (define-type QHState (U QuestionState ExpandingCNAMEs))
(: question-handler : CompiledZone Question UdpAddress -> (Transition QHState))
;; (: question-handler : CompiledZone Question UdpAddress -> (Transition QHState))
(define (question-handler zone q client-sock)
(retry-question (question-state zone q client-sock ((inst set DomainName)) 0)))
(retry-question (question-state zone q client-sock (set) 0)))
(: send-empty-reply : QHState Question -> (Transition QHState))
;; (: send-empty-reply : QHState Question -> (Transition QHState))
(define (send-empty-reply w q)
(transition w (send-message (answered-question q (empty-complete-answer)))))
(: retry-question : QHState -> (Transition QHState))
;; (: retry-question : QHState -> (Transition QHState))
(define (retry-question w)
(match w
[(question-state _ q _ _ 20) ;; TODO: is this a sensible limit?
@ -313,18 +287,18 @@
(log-debug (format "Referral for ~v id ~v to ~v servers ~v"
q referral-id (domain-labels zone-origin)
(map domain-labels (set-map nameserver-rrs rr-rdata-domain-name))))
(transition: w : QHState
((inst network-query QHState) client-sock
q
zone-origin
(map rr-rdata-domain-name (set->list nameserver-rrs))
referral-id)
(transition w
(network-query client-sock
q
zone-origin
(map rr-rdata-domain-name (set->list nameserver-rrs))
referral-id)
(name-endpoint referral-id
(subscriber: QHState (network-reply-pattern referral-id (wild))
(subscriber (network-reply referral-id (wild))
(match-state w
(on-message
[(network-reply (== referral-id) #f) ;; name-error/NXDOMAIN
(transition: w : QHState
(transition w
(delete-endpoint referral-id)
(send-message (answered-question q #f)))]
[(network-reply (== referral-id) ans)
@ -342,9 +316,8 @@
(log-debug "=-=-=-=-=-="))
(define nameserver-names
(list->set
(for/list: : (Listof DomainName)
([rr nameserver-rrs])
(rr-rdata-domain-name rr))))
(for/list ([rr nameserver-rrs])
(rr-rdata-domain-name rr))))
(sequence-actions
(retry-question (struct-copy question-state w
[nameservers-tried (set-union nameservers-tried
@ -353,30 +326,29 @@
[retry-count (+ old-retry-count 1)]))
(delete-endpoint referral-id)))])))))]
[(? complete-answer? ans)
(transition: w : QHState (send-message (answered-question q ans)))]
(transition w (send-message (answered-question q ans)))]
[(partial-answer base cnames)
(transition: (expanding-cnames q base (length cnames)) : QHState
((inst map (ActionTree QHState) DomainName)
(lambda: ([cname : DomainName])
;; TODO: record chains of CNAMEs to avoid pathologically-long chains
(define cname-q (cname-question cname q))
(list (send-message cname-q)
(let-fresh (subscription-id)
(name-endpoint subscription-id
(subscriber: QHState (answered-question-pattern cname-q (wild))
(match-state (expanding-cnames q acc remaining)
(on-message
[(answered-question (== cname-q) ans)
(let ()
(define new-acc (if ans (merge-answers acc ans) acc))
(define new-remaining (- remaining 1))
(define new-w (expanding-cnames q new-acc new-remaining))
(transition: new-w : QHState
(delete-endpoint subscription-id)
(if (zero? new-remaining)
(send-message (answered-question q new-acc))
'())))])))))))
cnames))])]))
(transition (expanding-cnames q base (length cnames))
(map (lambda (cname)
;; TODO: record chains of CNAMEs to avoid pathologically-long chains
(define cname-q (cname-question cname q))
(list (send-message cname-q)
(let-fresh (subscription-id)
(name-endpoint subscription-id
(subscriber (answered-question cname-q (wild))
(match-state (expanding-cnames q acc remaining)
(on-message
[(answered-question (== cname-q) ans)
(let ()
(define new-acc (if ans (merge-answers acc ans) acc))
(define new-remaining (- remaining 1))
(define new-w (expanding-cnames q new-acc new-remaining))
(transition new-w
(delete-endpoint subscription-id)
(if (zero? new-remaining)
(send-message (answered-question q new-acc))
'())))])))))))
cnames))])]))
(require "test-rrs.rkt")
(require racket/file)

52
resolver.rkt
View File

@ -1,4 +1,4 @@
#lang typed/racket/base
#lang racket/base
;;
;;; Copyright 2010, 2011, 2012, 2013 Tony Garnock-Jones <tonyg@ccs.neu.edu>
;;;
@ -27,12 +27,8 @@
(require "codec.rkt")
(require "zonedb.rkt")
(provide PartialAnswer
Referral
Answer
(struct-out partial-answer)
(provide (struct-out partial-answer)
(struct-out referral)
resolve-from-zone)
;; Rules:
@ -67,27 +63,22 @@
;; -- a CompleteAnswer (a complete answer ready to send),
;; -- #f (the domain name does not exist in the CompiledZone given),
;; -- a Referral (a referral to some other nameserver).
(define-type Answer (U CompleteAnswer PartialAnswer Referral #f))
;; A PartialAnswer is a (partial-answer CompleteAnswer ListOf<DomainName>)
;; A collection of relevant RRs together with some CNAMEs that need expanding.
(struct: partial-answer ([base : CompleteAnswer] [cnames : (Listof DomainName)]) #:transparent)
(define-type PartialAnswer partial-answer)
(struct partial-answer (base cnames) #:transparent)
;; A Referral is a (referral DomainName Set<RR> Set<RR>)
(struct: referral ([zone-origin : DomainName]
[nameserver-rrs : (Setof RR)]
[additional : (Setof RR)]) #:transparent)
(define-type Referral referral)
(struct referral (zone-origin nameserver-rrs additional) #:transparent)
(: answer-from-zone : Question CompiledZone (Option RR) -> Answer)
;; (: answer-from-zone : Question CompiledZone (Option RR) -> Answer)
;; An answer of #f here does NOT indicate a missing domain-name
;; (name-error/NXDOMAIN), but instead indicates that there are no
;; records matching the query in the database given. It's up to the
;; caller to decide what to do about that.
(define (answer-from-zone q zone start-of-authority)
(match-define (question name qtype qclass _) q)
(define: rrset : (Setof RR) (or (zone-ref zone name) (set)))
(define rrset (or (zone-ref zone name) (set)))
(define filtered-rrs (filter-rrs rrset qtype qclass))
(define cnames (filter-by-type rrset 'cname)) ;; TODO: filter by class too??
(define answer-set (set-union cnames filtered-rrs))
@ -105,9 +96,9 @@
[else ;; Kick off the algorithm for CNAME expansion from RFC 1034 4.3.2 step 3a
(partial-answer base (set-map cnames rr-rdata-domain-name))]))
(: closest-nameservers : DomainName CompiledZone -> (Setof RR))
;; (: closest-nameservers : DomainName CompiledZone -> (Setof RR))
(define (closest-nameservers name zone)
(let: search ((name : (Option DomainName) name))
(let search ((name name))
(cond
((not name)
;; We've walked up the tree past the root. Give up.
@ -124,45 +115,44 @@
;; Remove a label and keep looking.
(search (domain-parent name))))))
(: closest-untried-nameservers : Question CompiledZone (Setof DomainName) -> (Setof RR))
;; (: closest-untried-nameservers : Question CompiledZone (Setof DomainName) -> (Setof RR))
;; Returns a set of NS RRs in an arbitrary order.
(define (closest-untried-nameservers q zone nameservers-tried)
(define name (question-repr-name q))
(define name (question-name q))
(define ns-rrset (closest-nameservers name zone))
(list->set
(for/list: : (Listof RR) ([rr : RR ns-rrset]
#:when (not (set-member? nameservers-tried (rr-rdata-domain-name rr))))
rr)))
(for/list ([rr ns-rrset] #:when (not (set-member? nameservers-tried (rr-rdata-domain-name rr))))
rr)))
(: empty-answer : Question CompiledZone (Option RR) -> (Option CompleteAnswer))
;; (: empty-answer : Question CompiledZone (Option RR) -> (Option CompleteAnswer))
(define (empty-answer q zone start-of-authority)
(if (and start-of-authority ;; we are authoritative for something
(in-bailiwick? (question-repr-name q) (rr-name start-of-authority))
(in-bailiwick? (question-name q) (rr-name start-of-authority))
;; ^ for this in particular
(not (zone-includes-name? zone (question-repr-name q))))
(not (zone-includes-name? zone (question-name q))))
;; ^ there are no RRs at all for this q
;; NXDOMAIN/name-error: we definitely know there are no RRs at all for this q.
#f
;; A normal no-answers packet otherwise.
(empty-complete-answer)))
(: additional-section/a : CompiledZone (Listof DomainName) -> (Setof RR))
;; (: additional-section/a : CompiledZone (Listof DomainName) -> (Setof RR))
;; Implements the "additional section" rules from RFC 1035 (and the
;; rules for IPv6 from RFC 3596). Provides A and AAAA records for
;; names mentioned in the "names" list that have entries in "zone".
(define (additional-section/a zone names)
;; RFC 3596 (section 3) requires that we process AAAA here as well
;; as A.
(foldl (lambda: ([name : DomainName] [section : (Setof RR)])
(foldl (lambda (name section)
(set-union section
(set-filter (lambda: ([rr : RR])
(set-filter (lambda (rr)
(and (memv (rdata-type (rr-rdata rr)) '(a aaaa))
(eqv? (rr-class rr) 'in)))
(or (zone-ref zone name) ((inst set RR))))))
((inst set RR))
(or (zone-ref zone name) (set)))))
(set)
names))
(: resolve-from-zone : Question CompiledZone (Option RR) (Setof DomainName) -> Answer)
;; (: resolve-from-zone : Question CompiledZone (Option RR) (Setof DomainName) -> Answer)
(define (resolve-from-zone q zone start-of-authority nameservers-tried)
(or (answer-from-zone q zone start-of-authority)
(let ((best-nameservers (closest-untried-nameservers q zone nameservers-tried)))

20
test-rrs.rkt
View File

@ -1,4 +1,4 @@
#lang typed/racket/base
#lang racket/base
;;
;;; Copyright 2010, 2011, 2012, 2013 Tony Garnock-Jones <tonyg@ccs.neu.edu>
;;;
@ -33,16 +33,16 @@
30
10)))
(: A : (Listof Bytes) (Vector Integer Integer Integer Integer) -> RR)
(: A/ttl : (Listof Bytes) (Vector Integer Integer Integer Integer) Nonnegative-Integer -> RR)
(: MX : (Listof Bytes) Nonnegative-Integer (Listof Bytes) -> RR)
(: CNAME : (Listof Bytes) (Listof Bytes) -> RR)
(: NS : (Listof Bytes) (Listof Bytes) -> RR)
(: NS/ttl : (Listof Bytes) (Listof Bytes) Nonnegative-Integer -> RR)
(: TXT : (Listof Bytes) (Listof Bytes) -> RR)
;; (: A : (Listof Bytes) (Vector Integer Integer Integer Integer) -> RR)
;; (: A/ttl : (Listof Bytes) (Vector Integer Integer Integer Integer) Nonnegative-Integer -> RR)
;; (: MX : (Listof Bytes) Nonnegative-Integer (Listof Bytes) -> RR)
;; (: CNAME : (Listof Bytes) (Listof Bytes) -> RR)
;; (: NS : (Listof Bytes) (Listof Bytes) -> RR)
;; (: NS/ttl : (Listof Bytes) (Listof Bytes) Nonnegative-Integer -> RR)
;; (: TXT : (Listof Bytes) (Listof Bytes) -> RR)
(define (A n ip) (A/ttl n ip 30))
(define (A/ttl n ip ttl) (rr (domain n) 'in ttl (rdata-ipv4 'a (cast ip IPv4))))
(define (A/ttl n ip ttl) (rr (domain n) 'in ttl (rdata-ipv4 'a ip)))
(define (MX n p t) (rr (domain n) 'in 30 (rdata-mx 'mx p (domain t))))
(define (CNAME n1 n2) (rr (domain n1) 'in 30 (rdata-domain 'cname (domain n2))))
(define (NS n1 n2) (NS/ttl n1 n2 30))
@ -93,7 +93,7 @@
(list (NS '(#"a") '(#"ns" #"b"))
(NS '(#"b") '(#"ns" #"a"))))
(: test-port-number : -> Nonnegative-Integer)
;; (: test-port-number : -> Nonnegative-Integer)
(define (test-port-number)
(define p
(string->number

79
tk-dns.rkt
View File

@ -1,4 +1,4 @@
#lang typed/racket/base
#lang racket/base
;; DNS drivers using marketplace.
;;
;;; Copyright 2010, 2011, 2012, 2013 Tony Garnock-Jones <tonyg@ccs.neu.edu>
@ -22,62 +22,25 @@
(require racket/set)
(require racket/match)
(require "codec.rkt")
(require marketplace/sugar-typed)
(require marketplace/sugar)
(require marketplace/drivers/udp)
(require marketplace/support/pseudo-substruct)
(provide (struct-out bad-dns-packet-repr)
BadDnsPacket bad-dns-packet bad-dns-packet?
BadDnsPacketPattern bad-dns-packet-pattern bad-dns-packet-pattern?
(struct-out dns-request-repr)
DNSRequest dns-request dns-request?
DNSRequestPattern dns-request-pattern dns-request-pattern?
(struct-out dns-reply-repr)
DNSReply dns-reply dns-reply?
DNSReplyPattern dns-reply-pattern dns-reply-pattern?
(provide (struct-out bad-dns-packet)
(struct-out dns-request)
(struct-out dns-reply)
dns-read-driver
dns-write-driver
dns-spy)
(struct: (TDetail TSource TSink TReason)
bad-dns-packet-repr
([detail : TDetail] [source : TSource] [sink : TSink] [reason : TReason]) #:transparent)
(pseudo-substruct: (bad-dns-packet-repr Any UdpAddress UdpAddress Symbol)
BadDnsPacket bad-dns-packet bad-dns-packet?)
(pseudo-substruct: (bad-dns-packet-repr Any
(U Wild UdpAddressPattern)
(U Wild UdpAddressPattern)
(U Wild Symbol))
BadDnsPacketPattern bad-dns-packet-pattern bad-dns-packet-pattern?)
(struct bad-dns-packet (detail source sink reason) #:transparent)
(struct dns-request (message source sink) #:transparent)
(struct dns-reply (message source sink) #:transparent)
(struct: (TMessage TSource TSink)
dns-request-repr
([message : TMessage] [source : TSource] [sink : TSink]) #:transparent)
(pseudo-substruct: (dns-request-repr DNSMessage UdpAddress UdpAddress)
DNSRequest dns-request dns-request?)
(pseudo-substruct: (dns-request-repr (U Wild DNSMessage)
(U Wild UdpAddressPattern)
(U Wild UdpAddressPattern))
DNSRequestPattern dns-request-pattern dns-request-pattern?)
(struct: (TMessage TSource TSink)
dns-reply-repr
([message : TMessage] [source : TSource] [sink : TSink]) #:transparent)
(pseudo-substruct: (dns-reply-repr DNSMessage UdpAddress UdpAddress)
DNSReply dns-reply dns-reply?)
(pseudo-substruct: (dns-reply-repr (U Wild DNSMessage)
(U Wild UdpAddressPattern)
(U Wild UdpAddressPattern))
DNSReplyPattern dns-reply-pattern dns-reply-pattern?)
(: dns-read-driver : UdpAddress -> (Transition Void))
;; (: dns-read-driver : UdpAddress -> (Transition Void))
(define (dns-read-driver s)
(transition: (void) : Void
(at-meta-level: Void
(subscriber: Void (udp-packet-pattern (wild) s (wild))
(transition (void)
(at-meta-level
(subscriber (udp-packet (wild) s (wild))
(on-message
[(udp-packet source (== s) #"")
(begin (log-info "Debug dump packet received")
@ -91,26 +54,26 @@
((request) (dns-request message source s))
((response) (dns-reply message source s)))))])))))
(: dns-write-driver : UdpAddress -> (Transition Void))
;; (: dns-write-driver : UdpAddress -> (Transition Void))
(define (dns-write-driver s)
(: translate : DNSMessage UdpAddress -> (ActionTree Void))
;; (: translate : DNSMessage UdpAddress -> (ActionTree Void))
(define (translate message sink)
(with-handlers ((exn:fail? (lambda (e)
(send-message (bad-dns-packet message s sink 'unencodable)))))
(at-meta-level: Void
(at-meta-level
(send-message (udp-packet s sink (dns-message->packet message))))))
(transition: (void) : Void
(subscriber: Void (dns-request-pattern (wild) s (wild))
(transition (void)
(subscriber (dns-request (wild) s (wild))
(on-message
[(dns-request message (== s) sink) (translate message sink)]))
(subscriber: Void (dns-reply-pattern (wild) s (wild))
(subscriber (dns-reply (wild) s (wild))
(on-message
[(dns-reply message (== s) sink) (translate message sink)]))))
(: dns-spy : -> (Transition Void))
;; (: dns-spy : -> (Transition Void))
(define (dns-spy)
(transition: (void) : Void
(observe-publishers: Void (wild)
(transition (void)
(observe-publishers (wild)
(on-message
[(dns-request message source sink)
(begin (log-info (format "DNS: ~v asks ~v ~v~n : ~v"

102
zonedb.rkt
View File

@ -1,4 +1,4 @@
#lang typed/racket/base
#lang racket/base
;; Noddy representation of a zone, and various zone and RRSet utilities.
;;
;;; Copyright 2010, 2011, 2012, 2013 Tony Garnock-Jones <tonyg@ccs.neu.edu>
@ -25,10 +25,8 @@
(require "api.rkt")
(require "codec.rkt")
(require bitsyntax)
(require (rename-in marketplace/tr-struct-copy [tr-struct-copy struct-copy])) ;; PR13149
(provide CompiledZone
zone-ref
(provide zone-ref
zone-includes-name?
incorporate-complete-answer
zone-expire-name
@ -45,52 +43,47 @@
zone->bit-string
bit-string->zone)
(define-type RelativeSeconds Real)
(define-type AbsoluteSeconds Real)
(define-predicate absolute-seconds? AbsoluteSeconds)
;; (define-type RelativeSeconds Real)
;; (define-type AbsoluteSeconds Real)
;; (define-predicate absolute-seconds? AbsoluteSeconds)
(define absolute-seconds? real?)
;; An InfiniteLifetime is an (infinite-lifetime RelativeSeconds), a
;; specification of the TTL to use when sending a non-expiring RR to a
;; peer.
(struct: infinite-lifetime ([ttl : RelativeSeconds]) #:transparent)
(define-type InfiniteLifetime infinite-lifetime)
(struct infinite-lifetime (ttl) #:transparent)
;; An Expiry is either an AbsoluteSeconds or an InfiniteLifetime.
(define-type Expiry (U AbsoluteSeconds InfiniteLifetime))
;; A CompiledZone is a Hash<DomainName,Hash<RR,(or AbsoluteSeconds
;; InfiniteLifetime)>>, representing a collection of DNS RRSets
;; indexed by DomainName. Each RR in an RRSet either has an expiry
;; time associated with it or has an InfiniteLifetime associated with
;; it, in which case it should not expire.
(define-type CompiledZone (HashTable DomainName (HashTable RR Expiry)))
;; A Timers is a SetOf<(cons DomainName RelativeSeconds)>,
;; representing a collection of timeouts that should be set against
;; names to to see if their associated RRs have expired.
(define-type Timer (Pairof DomainName RelativeSeconds))
(define-type Timers (Setof Timer))
;; TODO: maybe store domain names big-end first? It'd make bailiwick
;; and subzone checks into prefix rather than suffix checks. It makes
;; domain names into paths through the DNS DB tree.
(: current-inexact-seconds : -> AbsoluteSeconds)
;; (: current-inexact-seconds : -> AbsoluteSeconds)
(define (current-inexact-seconds)
(/ (current-inexact-milliseconds) 1000.0))
(: still-valid? : Expiry AbsoluteSeconds -> Boolean)
;; (: still-valid? : Expiry AbsoluteSeconds -> Boolean)
(define (still-valid? expiry now)
(or (infinite-lifetime? expiry)
(>= expiry now)))
(: zone-ref : CompiledZone DomainName -> (Option (Setof RR)))
;; (: zone-ref : CompiledZone DomainName -> (Option (Setof RR)))
(define (zone-ref db name)
(define expirymap (hash-ref db name (lambda () #f)))
(and expirymap
(let ((now (current-inexact-seconds)))
(for/fold: ([acc : (Setof RR) (set)])
([resource : RR (in-hash-keys expirymap)])
(for/fold ([acc (set)]) ([resource (in-hash-keys expirymap)])
(define expiry (hash-ref expirymap resource))
(if (still-valid? expiry now)
(let ((new-ttl (if (infinite-lifetime? expiry)
@ -98,14 +91,14 @@
(- expiry now))))
(set-add acc
(struct-copy rr resource
[ttl (cast (exact-floor new-ttl) Nonnegative-Integer)])))
[ttl (exact-floor new-ttl)])))
acc)))))
(: zone-includes-name? : CompiledZone DomainName -> Boolean)
;; (: zone-includes-name? : CompiledZone DomainName -> Boolean)
(define (zone-includes-name? db name)
(hash-has-key? db name))
(: incorporate-rr : (Option AbsoluteSeconds) -> (RR CompiledZone -> CompiledZone))
;; (: incorporate-rr : (Option AbsoluteSeconds) -> (RR CompiledZone -> CompiledZone))
;; Incorporates the given RR into our database. If base-time is a
;; number of seconds, we treat the RR as having a TTL that decreases
;; as time goes by; otherwise base-time is #f, and we treat the RR as
@ -129,7 +122,7 @@
(infinite-lifetime (rr-ttl resource0))))
(define resource (struct-copy rr resource0 [ttl 0]))
(define name (rr-name resource))
(define old-expirymap (hash-ref db name (lambda () (ann #hash() (HashTable rr Expiry)))))
(define old-expirymap (hash-ref db name (lambda () #hash())))
(define old-expiry (hash-ref old-expirymap resource (lambda () 0)))
(cond
[(infinite-lifetime? old-expiry) ;; don't update TTL: the existing record should live forever
@ -139,15 +132,15 @@
[else ;; old record finite-lifetime but expiring after the new expiry: leave it alone
db]))
(: incorporate-complete-answer :
(Option CompleteAnswer) CompiledZone Boolean -> (Values CompiledZone Timers))
;; (: incorporate-complete-answer :
;; (Option CompleteAnswer) CompiledZone Boolean -> (Values CompiledZone Timers))
(define (incorporate-complete-answer ans db is-cache?)
(match ans
[#f
(values db (set))]
[(complete-answer ns us ds)
(define now (current-inexact-seconds))
(for/fold ([db db] [timers ((inst set Timer))])
(for/fold ([db db] [timers (set)])
([rr (in-list (append (set->list ns)
(set->list us)
(set->list ds)))]) ;; no in-sequences in typed racket
@ -156,15 +149,14 @@
(values ((incorporate-rr now) rr db)
(set-add timers (cons (rr-name rr) (rr-ttl rr))))))]))
(: zone-expire-name : CompiledZone DomainName AbsoluteSeconds -> CompiledZone)
;; (: zone-expire-name : CompiledZone DomainName AbsoluteSeconds -> CompiledZone)
;; Checks the given name to see if there are any expiring records, and
;; if so, removes them.
(define (zone-expire-name db name now-seconds)
(define empty-expirymap (ann #hash() (HashTable RR Expiry)))
(define empty-expirymap #hash())
(define old-expirymap (hash-ref db name (lambda () empty-expirymap)))
(define new-expirymap
(for/fold: ([acc : (HashTable RR Expiry) empty-expirymap])
([resource : RR (in-hash-keys old-expirymap)])
(for/fold ([acc empty-expirymap]) ([resource (in-hash-keys old-expirymap)])
(define expiry (hash-ref old-expirymap resource))
(if (still-valid? expiry now-seconds)
(hash-set acc resource expiry)
@ -173,33 +165,33 @@
(hash-remove db name)
(hash-set db name new-expirymap)))
(: zone-expire : CompiledZone -> (Values CompiledZone Timers))
;; (: zone-expire : CompiledZone -> (Values CompiledZone Timers))
;; Used to freshen a saved zone when it is loaded from disk.
(define (zone-expire zone)
(define now-seconds (current-inexact-seconds))
(for/fold: ([zone : CompiledZone zone] [timers : Timers (set)])
([name : DomainName (in-hash-keys zone)])
(for/fold ([zone zone] [timers (set)])
([name (in-hash-keys zone)])
(define new-zone (zone-expire-name zone name now-seconds))
(define expirymap (hash-ref new-zone name (lambda () #f)))
(values new-zone
(if expirymap
(set-union (list->set
(map (lambda: ([e : AbsoluteSeconds]) (cons name (- e now-seconds)))
(map (lambda (e) (cons name (- e now-seconds)))
(filter absolute-seconds? (hash-values expirymap))))
timers)
timers))))
(: empty-zone-db : -> CompiledZone)
;; (: empty-zone-db : -> CompiledZone)
(define (empty-zone-db)
(make-immutable-hash))
(: compile-zone-db : (Listof RR) -> CompiledZone)
;; (: compile-zone-db : (Listof RR) -> CompiledZone)
;; Builds an immutable hash table from the given RRs, suitable for
;; quickly looking up answers to queries.
(define (compile-zone-db rrs)
(foldl (incorporate-rr #f) (empty-zone-db) rrs))
(: in-bailiwick? : DomainName DomainName -> Boolean)
;; (: in-bailiwick? : DomainName DomainName -> Boolean)
;; Answers #t iff dn falls within the bailiwick of the zone with
;; origin o.
(define (in-bailiwick? dn o)
@ -207,23 +199,23 @@
(let ((p (domain-parent dn)))
(and p (in-bailiwick? p o)))))
(: set-filter : (All (X) (X -> Boolean) (Setof X) -> (Setof X)))
;; (: set-filter : (All (X) (X -> Boolean) (Setof X) -> (Setof X)))
;; Retains only those elements of its argument for which the predicate
;; answers #t.
(define (set-filter predicate in)
(for/fold: ([acc : (Setof X) (set)]) ([x : X (in-list (set->list in))])
(for/fold ([acc (set)]) ([x (in-list (set->list in))])
(if (predicate x) (set-add acc x) acc)))
(: filter-by-type : (Setof RR) RRType -> (Setof RR))
;; (: filter-by-type : (Setof RR) RRType -> (Setof RR))
;; Selects only those members of rrset having rr-type type.
(define (filter-by-type rrset type)
(define p? (rdata-type-pred type))
(set-filter (lambda: ([rr : RR]) (p? (rr-rdata rr))) rrset))
(set-filter (lambda (rr) (p? (rr-rdata rr))) rrset))
(: no-rrs : (Setof RR))
;; (: no-rrs : (Setof RR))
(define no-rrs (set))
(: filter-rrs : (Setof RR) QueryType QueryClass -> (Setof RR))
;; (: filter-rrs : (Setof RR) QueryType QueryClass -> (Setof RR))
;; Returns a set like its argument with RRs not matching the given
;; type and class removed.
(define (filter-rrs rrs qtype qclass)
@ -237,10 +229,10 @@
(define filtered-by-type-and-class
(case qclass
((*) filtered-by-type)
(else (set-filter (lambda: ([rr : RR]) (eqv? (rr-class rr) qclass)) filtered-by-type))))
(else (set-filter (lambda (rr) (eqv? (rr-class rr) qclass)) filtered-by-type))))
filtered-by-type-and-class)
(: rr-set->list : (Setof RR) -> (Listof RR))
;; (: rr-set->list : (Setof RR) -> (Listof RR))
;; Like set->list, but places all CNAME records first.
;; This is apparently to work around bugs in old versions of BIND?
;;
@ -264,11 +256,11 @@
(append (cname-sort (set->list cnames))
(set->list (set-subtract rrs cnames))))
(: rr-rdata-domain-name : RR -> DomainName)
;; (: rr-rdata-domain-name : RR -> DomainName)
(define (rr-rdata-domain-name rr)
(rdata-domain-name (cast (rr-rdata rr) rdata-domain)))
(rdata-domain-name (rr-rdata rr)))
(: cname-sort : (Listof RR) -> (Listof RR))
;; (: cname-sort : (Listof RR) -> (Listof RR))
;; Produce an ordering of the CNAMEs given that respects their
;; "causality". For example, if a CNAME b and b CNAME c, then the RRs
;; will be presented in that order (and not the other order, with b
@ -277,11 +269,9 @@
(define lhss (list->set (map rr-name cnames)))
(define rhss (list->set (map rr-rdata-domain-name cnames)))
(define roots (set->list (set-subtract lhss rhss))) ;; Nodes not the targets of some edge.
(: targets-of : DomainName -> (Listof RR))
(define (targets-of name) (filter (lambda: ([rr : RR]) (equal? (rr-name rr) name)) cnames))
(let: iterate ((remaining : (Listof DomainName) roots)
(seen : (Setof DomainName) (set))
(acc : (Listof RR) '()))
;; (: targets-of : DomainName -> (Listof RR))
(define (targets-of name) (filter (lambda (rr) (equal? (rr-name rr) name)) cnames))
(let iterate ((remaining roots) (seen (set)) (acc '()))
(if (null? remaining)
(reverse acc)
(let ((source (car remaining)))
@ -293,12 +283,12 @@
(set-add seen source)
(append rrs acc))))))))
(: zone->bit-string : CompiledZone -> BitString)
;; (: zone->bit-string : CompiledZone -> BitString)
;; Produces a serialized form of the zone suitable for saving to disk.
(define (zone->bit-string zone)
(for/fold: ([acc : BitString (bit-string)]) ([name : DomainName (in-hash-keys zone)])
(for/fold ([acc (bit-string)]) ([name (in-hash-keys zone)])
(define rrmap (hash-ref zone name))
(for/fold: ([acc : BitString acc]) ([rr : RR (in-hash-keys rrmap)])
(for/fold ([acc acc]) ([rr (in-hash-keys rrmap)])
(define expiry (hash-ref rrmap rr))
(bit-string-append
acc
@ -308,7 +298,7 @@
[else
(bit-string (rr :: (t:rr)) 0 ((exact-truncate expiry) :: bits 32))])))))
(: bit-string->zone : BitString -> CompiledZone)
;; (: bit-string->zone : BitString -> CompiledZone)
;; Produces a deserialized form of the zone. Suitable for use in loading from disk.
(define (bit-string->zone bs)
(define now (current-inexact-seconds))