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dns.bend relies on unsafe/foreign

raw source on the hub · import bend-kit-dns@0.4.0.2/dns.bend as Dns

DNS codec and host lookup. Source: https://github.com/paymog/bend-kit/tree/main/dns

2 imports
import Base
import 0x096635686408886b7d907f16c4550317/wire.bend as Wire

Types

type Cur source · line 10 · raw

Data

type RR source · line 13 · raw

Data

type Try source · line 381 · raw

Data

One attempt's outcome: try again, or this answer (None: no address).

Definitions

def u8 source · line 18 · raw

@s:String -> Maybe<&2, Cur>

def u16.lo source · line 25 · raw

@hi:U32 -> @m:Maybe<&2, Cur> -> Maybe<&2, Cur>

def u16.go source · line 32 · raw

@m:Maybe<&2, Cur> -> Maybe<&2, Cur>

def u16 source · line 39 · raw

@s:String -> Maybe<&2, Cur>

def skip.if source · line 42 · raw

@+s:String -> @+n:Nat -> @short:Bool -> Maybe<&2, String>

def skip source · line 49 · raw

@+s:String -> @+n:Nat -> Maybe<&2, String>

def then source · line 52 · raw

@m:Maybe<&2, String> -> @n:Nat -> Maybe<&2, String>

def push16 source · line 59 · raw

@+n:U32 -> @acc:String -> String

def label.ok source · line 65 · raw

@+l:String -> Bool

def label.ascii source · line 69 · raw

@s:String -> Bool

def labels.ok source · line 76 · raw

@xs:List<&2, String> -> Bool

def labels.put source · line 83 · raw

@xs:List<&2, String> -> @acc:String -> String

def query.if source · line 90 · raw

@+id:U32 -> @xs:List<&2, String> -> @ok:Bool -> Maybe<&2, String>

def query.labels source · line 98 · raw

@+id:U32 -> @+xs:List<&2, String> -> Maybe<&2, String>

def strip_dot.if source · line 101 · raw

@+s:String -> @dot:Bool -> String

def strip_dot source · line 108 · raw

@+s:String -> String

def query source · line 112 · raw

@id:U32 -> @name:String -> Maybe<&2, String>

RFC 1035 §4.1: a standard query for the A record of name.

def name.skip source · line 119 · raw

@fuel:Nat -> @s:String -> Maybe<&2, String>

§4.1.4: a name is labels ending in a zero octet, or a two-octet pointer.

def name.then source · line 130 · raw

@m:Maybe<&2, String> -> @n:Nat -> Maybe<&2, String>

def dotted source · line 137 · raw

@s:String -> String

def rr.f source · line 148 · raw

@+r:String -> @+len:U32 -> @a:Bool -> RR

def rr.data source · line 155 · raw

@+r:String -> @+len:U32 -> @a:Bool -> @short:Bool -> RR

def rr.e source · line 162 · raw

@+ty:U32 -> @+cl:U32 -> @m:Maybe<&2, Cur> -> RR

def rr.d source · line 169 · raw

@ty:U32 -> @cl:U32 -> @m:Maybe<&2, String> -> RR

def rr.c source · line 176 · raw

@ty:U32 -> @m:Maybe<&2, Cur> -> RR

def rr.b source · line 183 · raw

@m:Maybe<&2, Cur> -> RR

def rr.a source · line 190 · raw

@m:Maybe<&2, String> -> RR

def rr source · line 198 · raw

@+s:String -> RR

§4.1.3: NAME, TYPE, CLASS, TTL, RDLENGTH, RDATA.

def answers.scan source · line 202 · raw

@fuel:Nat -> @r:RR -> Maybe<&2, String>

fuel = records left. The first A record wins; CNAMEs before it are skipped.

def questions source · line 215 · raw

@fuel:Nat -> @m:Maybe<&2, String> -> Maybe<&2, String>

def body.go source · line 222 · raw

@an:U32 -> @m:Maybe<&2, String> -> Maybe<&2, String>

def body.an source · line 229 · raw

@qd:U32 -> @m:Maybe<&2, Cur> -> Maybe<&2, String>

def body.qd source · line 236 · raw

@m:Maybe<&2, Cur> -> Maybe<&2, String>

def flags.ok source · line 244 · raw

@+f:U32 -> Bool

§4.1.1: QR set, opcode QUERY, not truncated, RCODE 0.

def head.flags.if source · line 247 · raw

@r:String -> @ok:Bool -> Maybe<&2, String>

def head.flags source · line 254 · raw

@m:Maybe<&2, Cur> -> Maybe<&2, String>

def head.id.if source · line 261 · raw

@r:String -> @ok:Bool -> Maybe<&2, String>

def head.id source · line 268 · raw

@id:U32 -> @m:Maybe<&2, Cur> -> Maybe<&2, String>

def answer source · line 276 · raw

@id:U32 -> @msg:String -> Maybe<&2, String>

The IPv4 address the response gives for the query with this id.

def nameservers.add source · line 282 · raw

@+line:String -> @rest:List<&2, String> -> @hit:Bool -> List<&2, String>

def nameservers.go source · line 289 · raw

@xs:List<&2, String> -> List<&2, String>

def nameservers source · line 297 · raw

@conf:String -> List<&2, String>

Every nameserver line, in file order.

def nameserver.first source · line 300 · raw

@xs:List<&2, String> -> Maybe<&2, String>

def nameserver source · line 308 · raw

@conf:String -> Maybe<&2, String>

The first nameserver line of a resolv.conf.

def none source · line 314 · raw

IO(Maybe<&2, String>)

def list.append source · line 317 · raw

@xs:List<&2, String> -> @ys:List<&2, String> -> List<&2, String>

def list.one source · line 324 · raw

@+x:String -> List<&2, String>

def list.any source · line 327 · raw

@+xs:List<&2, String> -> Bool

def list.first source · line 334 · raw

@xs:List<&2, String> -> Maybe<&2, String>

def ipv4.go source · line 341 · raw

@s:String -> Bool

def ipv4 source · line 349 · raw

@+s:String -> Bool

Digits and dots; TCP.connect rejects anything else that is not an address.

def ipv6.ch source · line 352 · raw

@+c:U32 -> Bool

def ipv6.go source · line 359 · raw

@s:String -> Bool

def ipv6.has source · line 366 · raw

@s:String -> Bool

def ipv6 source · line 374 · raw

@+s:String -> Bool

Bracket-free IPv6 text; connect validates the address.

def ip source · line 377 · raw

@+s:String -> Bool

def try.pure source · line 385 · raw

@s:Socket -> @t:Try -> IO(Pair(Socket, Try))

def try.from source · line 389 · raw

@s:Socket -> @+ns:String -> @id:U32 -> @hpd:Pair(String, Pair(U32, String)) -> IO(Pair(Socket, Try))

A datagram from anyone but the nameserver's port 53 is ignored (retried).

def try.back source · line 393 · raw

@ns:String -> @id:U32 -> @m:Pair(Socket, Result<&1, &1, Pair(U32, String), Pair(String, Pair(U32, String))>) -> IO(Pair(Socket, Try))

def try.sent source · line 402 · raw

@ns:String -> @id:U32 -> @m:Pair(Socket, Result<&1, &1, Pair(U32, String), Unit>) -> IO(Pair(Socket, Try))

§4.2.1 and resolv.conf defaults: 5 s per attempt.

def try.once source · line 412 · raw

@s:Socket -> @+ns:String -> @id:U32 -> @q:String -> IO(Pair(Socket, Try))

def try.close source · line 417 · raw

@s:Socket -> @r:Maybe<&2, String> -> IO(Maybe<&2, String>)

def tries.end source · line 422 · raw

@st:Pair(Socket, Try) -> IO(Maybe<&2, String>)

def tries source · line 431 · raw

@fuel:Nat -> @+ns:String -> @+id:U32 -> @+q:String -> @st:Pair(Socket, Try) -> IO(Maybe<&2, String>)

fuel: attempts left (resolv.conf's default is 2).

def resolve.sock source · line 445 · raw

@ns:String -> @id:U32 -> @q:String -> @r:Result<&1, &1, Pair(U32, String), Socket> -> IO(Maybe<&2, String>)

def resolve.q source · line 452 · raw

@ns:String -> @id:U32 -> @q:Maybe<&2, String> -> IO(Maybe<&2, String>)

def resolve.id source · line 462 · raw

@name:String -> @ns:String -> @r:Result<&1, &1, Pair(U32, String), U32> -> IO(Maybe<&2, String>)

§7.3: a random id makes forged answers harder to land.

def resolve.ns source · line 470 · raw

@name:String -> @ns:Maybe<&2, String> -> IO(Maybe<&2, String>)

def resolve.at source · line 480 · raw

@+host:String -> @ns:String -> IO(Maybe<&2, String>)

Ask one nameserver. Tests use this; resolve reads /etc/resolv.conf.

def conf.text source · line 483 · raw

@r:Result<&1, &1, Pair(U32, String), String> -> String

def resolve.n3 source · line 491 · raw

@+name:String -> @xs:List<&2, String> -> IO(Maybe<&2, String>)

ponytail: 3 nameservers; a longer resolv.conf ignores the rest

def resolve.n2b source · line 498 · raw

@+name:String -> @rest:List<&2, String> -> @ip:Maybe<&2, String> -> IO(Maybe<&2, String>)

def resolve.n2 source · line 505 · raw

@+name:String -> @xs:List<&2, String> -> IO(Maybe<&2, String>)

def resolve.n1b source · line 514 · raw

@+name:String -> @rest:List<&2, String> -> @ip:Maybe<&2, String> -> IO(Maybe<&2, String>)

def resolve.list source · line 521 · raw

@+name:String -> @xs:List<&2, String> -> IO(Maybe<&2, String>)

def resolve.read source · line 530 · raw

@name:String -> @m:Pair(File, Result<&1, &1, Pair(U32, String), String>) -> IO(Maybe<&2, String>)

def resolve.conf source · line 536 · raw

@name:String -> @r:Result<&1, &1, Pair(U32, String), File> -> IO(Maybe<&2, String>)

def resolve.dns source · line 545 · raw

@name:String -> IO(Maybe<&2, String>)

def hosts.on_line source · line 551 · raw

@+name:String -> @ns:List<&2, String> -> Bool

def hosts.line.all source · line 558 · raw

@+name:String -> @xs:List<&2, String> -> List<&2, String>

def hosts.sp source · line 565 · raw

@+c:U32 -> @tab:Bool -> U32

def hosts.flat source · line 572 · raw

@s:String -> String

def hosts.scan.all source · line 579 · raw

@xs:List<&2, String> -> @+name:String -> @acc:List<&2, String> -> List<&2, String>

def hosts.all source · line 588 · raw

@+name:String -> @text:String -> List<&2, String>

Every address for name in an /etc/hosts file. The name is already lowercase.

def hosts source · line 592 · raw

@+name:String -> @text:String -> Maybe<&2, String>

First address for name in an /etc/hosts file. The name is already lowercase.

def lookup.split source · line 595 · raw

@+s:String -> List<&2, String>

def resolve.literal.all source · line 604 · raw

@+host:String -> List<&2, String>

Literals and localhost without the OS (for laws and fast paths).

def resolve.literal source · line 609 · raw

@+host:String -> Maybe<&2, String>

def resolve.all.got source · line 612 · raw

@r:Result<&1, &1, Pair(U32, String), String> -> IO(List<&2, String>)

def resolve.all.os source · line 619 · raw

@+name:String -> IO(List<&2, String>)

def resolve.all.dns.one source · line 624 · raw

@m:Maybe<&2, String> -> IO(List<&2, String>)

def resolve.all.dns source · line 632 · raw

@+name:String -> IO(List<&2, String>)

ponytail: UDP path still asks for A records only

def resolve.all.from source · line 637 · raw

@+name:String -> @+xs:List<&2, String> -> IO(List<&2, String>)

def resolve.all.text source · line 644 · raw

@+name:String -> @r:Result<&1, &1, Pair(U32, String), String> -> IO(List<&2, String>)

def resolve.all.opened source · line 651 · raw

@+name:String -> @m:Pair(File, Result<&1, &1, Pair(U32, String), String>) -> IO(List<&2, String>)

def resolve.all.hosts source · line 657 · raw

@+name:String -> @r:Result<&1, &1, Pair(U32, String), File> -> IO(List<&2, String>)

def resolve.all.pick source · line 666 · raw

@+host:String -> @+xs:List<&2, String> -> IO(List<&2, String>)

def resolve.all source · line 673 · raw

@+host:String -> IO(List<&2, String>)

def resolve.all.ask source · line 676 · raw

@+name:String -> IO(List<&2, String>)

def resolve.all.pure.pick source · line 681 · raw

@+host:String -> @+xs:List<&2, String> -> IO(List<&2, String>)

def resolve.all.pure source · line 688 · raw

@+host:String -> IO(List<&2, String>)

def resolve.pure source · line 691 · raw

@+host:String -> IO(Maybe<&2, String>)

def resolve source · line 697 · raw

@+host:String -> IO(Maybe<&2, String>)

First address from resolve.all (getaddrinfo order when the OS resolves).

Effects (foreign code)

effect lookup.all source · line 599 · raw

@host:String -> IO(Result<&1, &1, Pair(U32, String), String>)

OS resolver: every address, NUL-separated in getaddrinfo order.

foreign: effs/dns.c, effs/dns.js