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Tom Thorogood 17c1bc6792
Eliminate lexer goroutines (#792)
* Eliminate zlexer goroutine

This replaces the zlexer goroutine and channels with a zlexer struct
that maintains state and provides a channel-like API.

* Eliminate klexer goroutine

This replaces the klexer goroutine and channels with a klexer struct
that maintains state and provides a channel-like API.

* Merge scan into zlexer and klexer

This does result in tokenText existing twice, but it's pretty simple
and small so it's not that bad.

* Avoid using text/scanner.Position to track position

* Track escape within zlexer.Next

* Avoid zl.commt check on space and tab in zlexer

* Track stri within zlexer.Next

* Track comi within zlexer.Next

There is one special case at the start of a comment that needs to be
handled, otherwise this is as simple as stri was.

* Use a single token buffer in zlexer

This is safe as there is never both a non-empty string buffer and a
non-empty comment buffer.

* Don't hardcode length of zl.tok in zlexer

* Eliminate lex.length field

This is always set to len(l.token) and is only queried in a few places.

It was added in 47cc5b052d without any
obvious need.

* Add whitespace to klexer.Next

* Track lex within klexer.Next

* Use a strings.Builder in klexer.Next

* Simplify : case in klexer.Next

* Add whitespace to zlexer.Next

* Change for loop style in zlexer.Next and klexer.Next

* Surface read errors in zlexer

* Surface read errors from klexer

* Remove debug line from parseKey

* Rename tokenText to readByte

* Make readByte return ok bool

Also change the for loop style to match the Next for loops.

* Make readByte errors sticky

klexer.Next calls readByte separately from within the loop. Without
readByte being sticky, an error that occurs during that readByte call
may be lost.

* Panic in testRR if the error is non-nil

* Add whitespace and unify field setting in zlexer.Next

* Remove eof fields from zlexer and klexer

With readByte having sticky errors, this no longer needed. zl.eof = true
was also in the wrong place and could mask an unbalanced brace error.

* Merge zl.tok blocks in zlexer.Next

* Split the tok buffer into separate string and comment buffers

The invariant of stri > 0 && comi > 0 never being true was broken when
x == '\n' && !zl.quote && zl.commt && zl.brace != 0 (the
"If not in a brace this ends the comment AND the RR" block).

Split the buffer back out into two separate buffers to avoid clobbering.

* Replace token slices with arrays in zlexer

* Add a NewRR benchmark

* Move token buffers into zlexer.Next

These don't need to be retained across Next calls and can be stack
allocated inside Next. This drastically reduces memory consumption as
they accounted for nearly half of all the memory used.

name      old alloc/op   new alloc/op   delta
NewRR-12    9.72kB ± 0%    4.98kB ± 0%  -48.72%  (p=0.000 n=10+10)

* Add a ReadRR benchmark

Unlike NewRR, this will use an io.Reader that does not implement any
methods aside from Read. In particular it does not implement
io.ByteReader.

* Avoid using a bufio.Reader for io.ByteReader readers

At the same time use a smaller buffer size of 1KiB rather than the
bufio.NewReader default of 4KiB.

name       old time/op    new time/op    delta
NewRR-12     11.0µs ± 3%     9.5µs ± 2%  -13.77%  (p=0.000 n=9+10)
ReadRR-12    11.2µs ±16%     9.8µs ± 1%  -13.03%  (p=0.000 n=10+10)

name       old alloc/op   new alloc/op   delta
NewRR-12     4.98kB ± 0%    0.81kB ± 0%  -83.79%  (p=0.000 n=10+10)
ReadRR-12    4.87kB ± 0%    1.82kB ± 0%  -62.73%  (p=0.000 n=10+10)

name       old allocs/op  new allocs/op  delta
NewRR-12       19.0 ± 0%      17.0 ± 0%  -10.53%  (p=0.000 n=10+10)
ReadRR-12      19.0 ± 0%      19.0 ± 0%     ~     (all equal)

ReadRR-12    11.2µs ±16%     9.8µs ± 1%  -13.03%  (p=0.000 n=10+10)

* Surface any remaining comment from zlexer.Next

* Improve comment handling in zlexer.Next

This both fixes a regression where comments could be lost under certain
circumstances and now emits comments that occur within braces.

* Remove outdated comment from zlexer.Next and klexer.Next

* Delay converting LF to space in braced comment

* Fixup TestParseZoneComments

* Remove tokenUpper field from lex

Not computing this for every token, and instead only
when needed is a substantial performance improvement.

name       old time/op    new time/op    delta
NewRR-12     9.56µs ± 0%    6.30µs ± 1%  -34.08%  (p=0.000 n=9+10)
ReadRR-12    9.93µs ± 1%    6.67µs ± 1%  -32.77%  (p=0.000 n=10+10)

name       old alloc/op   new alloc/op   delta
NewRR-12       824B ± 0%      808B ± 0%   -1.94%  (p=0.000 n=10+10)
ReadRR-12    1.83kB ± 0%    1.82kB ± 0%   -0.87%  (p=0.000 n=10+10)

name       old allocs/op  new allocs/op  delta
NewRR-12       17.0 ± 0%      17.0 ± 0%     ~     (all equal)
ReadRR-12      19.0 ± 0%      19.0 ± 0%     ~     (all equal)

* Update ParseZone documentation to match comment changes

The zlexer code was changed to return comments more often, so update the
ParseZone documentation to match.
2018-10-15 17:42:31 +10:30
dnsutil util.TrimDomainName() fails when origin doesn't end in dot (#559) 2017-11-08 18:19:10 +00:00
vendor/golang.org/x Run dep ensure -update (#770) 2018-10-05 18:29:45 +01:00
.codecov.yml Add codecov yaml to not fail the build (#600) 2017-12-06 10:36:23 +00:00
.gitignore gitignore update 2013-10-15 13:22:35 +00:00
.travis.yml Test coverage for all packages and merge Travis builds (#781) 2018-10-09 18:46:58 +01:00
AUTHORS add AUTHOR file 2014-02-10 17:15:49 +00:00
CONTRIBUTORS Correctly set the Source IP to the received Destination IP (#524) 2017-09-29 10:38:26 +01:00
COPYRIGHT Remove all copyright notices 2014-09-11 20:57:37 +01:00
Gopkg.lock Run dep ensure -update (#770) 2018-10-05 18:29:45 +01:00
Gopkg.toml Run dep ensure -update (#770) 2018-10-05 18:29:45 +01:00
LICENSE Update the copy right for the original GO files 2013-05-12 16:07:06 +02:00
Makefile.fuzz Add fuzzing framework (#580) 2017-11-23 09:34:31 +00:00
Makefile.release Release: plain push is also needed 2018-01-10 08:17:22 +00:00
README.md add user link (#790) 2018-10-12 22:15:26 +01:00
client.go Fix dominikh/go-tools nits (#758) 2018-09-27 04:02:05 +09:30
client_test.go Fix race on loop variable in TestConcurrentExchanges (#773) 2018-10-04 07:24:09 +01:00
clientconfig.go fix: panicing on options parsing. (#642) 2018-03-01 06:22:09 -08:00
clientconfig_test.go fix: panicing on options parsing. (#642) 2018-03-01 06:22:09 -08:00
compress_generate.go Fixed len computation when size just goes beyond 14 bits (#668) 2018-05-16 07:20:13 +01:00
dane.go Improve performance by addressing some low hanging fruit. (#444) 2017-02-02 07:33:49 +00:00
defaults.go ClassANY: don't convert CLASS255 to ANY (#618) 2018-01-07 17:57:04 +00:00
dns.go copyHeader is redundant (#672) 2018-05-10 14:50:26 +01:00
dns_bench_test.go Tests updates (#556) 2017-11-08 10:01:19 +00:00
dns_test.go Fix dominikh/go-tools nits (#758) 2018-09-27 04:02:05 +09:30
dnssec.go Remove redundant parenthesis (#727) 2018-08-16 17:05:27 +01:00
dnssec_keygen.go 458+dep (#591) 2017-11-27 10:49:53 +00:00
dnssec_keyscan.go Eliminate lexer goroutines (#792) 2018-10-15 17:42:31 +10:30
dnssec_privkey.go Use RFC 8032 functions added to x/crypto/ed25519 (#715) 2018-07-25 13:01:44 +01:00
dnssec_test.go Eliminate lexer goroutines (#792) 2018-10-15 17:42:31 +10:30
doc.go ExchangeWithDialer does not exist anymore (#666) 2018-04-06 12:05:09 +01:00
duplicate.go Add IsDuplicate function (#699) 2018-06-23 09:12:31 +01:00
duplicate_generate.go Add IsDuplicate function (#699) 2018-06-23 09:12:31 +01:00
duplicate_test.go Add IsDuplicate function (#699) 2018-06-23 09:12:31 +01:00
dyn_test.go Remove all copyright notices 2014-09-11 20:57:37 +01:00
edns.go Remove redundant parenthesis (#727) 2018-08-16 17:05:27 +01:00
edns_test.go Fix EDNS Extended RCODE (#517) 2017-10-13 17:21:46 +02:00
example_test.go fix a stupid mistake "undefined: zone" 2015-09-30 09:42:47 -07:00
format.go Remove WKS support 2016-06-05 08:23:44 +01:00
fuzz.go Add fuzzing framework (#580) 2017-11-23 09:34:31 +00:00
generate.go Eliminate lexer goroutines (#792) 2018-10-15 17:42:31 +10:30
generate_test.go Allows larger offset in $GENERATE (#776) 2018-10-05 18:30:27 +01:00
issue_test.go Tests updates (#556) 2017-11-08 10:01:19 +00:00
labels.go Remove redundant parenthesis (#727) 2018-08-16 17:05:27 +01:00
labels_test.go Cleanup: gofmt -w -s *.go (#548) 2017-11-03 16:15:35 +00:00
leak_test.go WIP: DNS-over-HTTPS support for Client.Exchange API (#671) 2018-05-16 08:54:01 +01:00
length_test.go Fixed len computation when size just goes beyond 14 bits (#668) 2018-05-16 07:20:13 +01:00
listen_go111.go Use correct build constraints for listen_*.go files (#750) 2018-09-26 09:12:54 +01:00
listen_go_not111.go Use correct build constraints for listen_*.go files (#750) 2018-09-26 09:12:54 +01:00
msg.go Optimise sprintX functions in types.go (#757) 2018-10-06 02:06:59 +09:30
msg_generate.go Lint: use ignore-this on generated files (#596) 2017-12-06 10:02:47 +00:00
msg_helpers.go Optimise sprintX functions in types.go (#757) 2018-10-06 02:06:59 +09:30
msg_helpers_test.go Fix unpackString bug: 127 DEL is unprintable (#755) 2018-09-27 07:47:48 +01:00
msg_test.go NSEC type bitmap packing bug (#768) 2018-10-04 07:39:45 +01:00
nsecx.go NSEC/3 Cover+Match cleanup (#479) 2017-04-12 19:47:48 +01:00
nsecx_test.go Handle empty NSEC3 salt in scanner (#677) 2018-05-14 20:07:52 +01:00
parse_test.go Eliminate lexer goroutines (#792) 2018-10-15 17:42:31 +10:30
privaterr.go Eliminate lexer goroutines (#792) 2018-10-15 17:42:31 +10:30
privaterr_test.go Test: remove all Logf/Log (#547) 2017-11-03 15:50:01 +00:00
rawmsg.go Cleanup and removals (#377) 2016-06-13 19:44:38 +01:00
remote_test.go Add remote test 2015-08-22 10:50:07 +01:00
reverse.go Golint fixes (#456) 2017-02-15 20:40:16 +00:00
rr_test.go Eliminate lexer goroutines (#792) 2018-10-15 17:42:31 +10:30
sanitize.go Add IsDuplicate function (#699) 2018-06-23 09:12:31 +01:00
sanitize_test.go Tests updates (#556) 2017-11-08 10:01:19 +00:00
scan.go Eliminate lexer goroutines (#792) 2018-10-15 17:42:31 +10:30
scan_rr.go Eliminate lexer goroutines (#792) 2018-10-15 17:42:31 +10:30
scan_test.go Eliminate lexer goroutines (#792) 2018-10-15 17:42:31 +10:30
serve_mux.go Rework and optimise ServeMux (#754) 2018-09-27 07:48:02 +01:00
serve_mux_test.go Rework and optimise ServeMux (#754) 2018-09-27 07:48:02 +01:00
server.go Hold srv.lock while calling SetReadDeadline (#780) 2018-10-09 18:46:15 +01:00
server_test.go Use an atomic int32 in checkInProgressQueriesAtShutdownServer (#779) 2018-10-09 18:43:08 +01:00
sig0.go Fix dominikh/go-tools nits (#758) 2018-09-27 04:02:05 +09:30
sig0_test.go Lowercase all error msg from the tests 2015-11-26 14:12:38 +00:00
singleinflight.go Implement outstanding query detection. 2013-08-24 02:28:58 +00:00
smimea.go Golint fixes (#456) 2017-02-15 20:40:16 +00:00
tlsa.go Fix for miekg/dns issue #289: support the SMIMEA record (#410) 2016-10-17 18:09:52 +01:00
tsig.go Fix TSIG bug releated to ID substitution (#504) 2017-08-12 20:21:44 +01:00
tsig_test.go Fix TSIG bug releated to ID substitution (#504) 2017-08-12 20:21:44 +01:00
types.go Optimise sprintX functions in types.go (#757) 2018-10-06 02:06:59 +09:30
types_generate.go copyHeader is redundant (#672) 2018-05-10 14:50:26 +01:00
types_test.go Optimise sprintX functions in types.go (#757) 2018-10-06 02:06:59 +09:30
udp.go Rollback PR #738 because it breaks compatibility with Windows (#765) 2018-09-29 10:25:59 +01:00
udp_test.go Rollback PR #738 because it breaks compatibility with Windows (#765) 2018-09-29 10:25:59 +01:00
udp_windows.go Rollback PR #738 because it breaks compatibility with Windows (#765) 2018-09-29 10:25:59 +01:00
update.go An update msg can have multiple, different prerequests and also multiple, 2016-02-27 12:58:10 +01:00
update_test.go ClassANY: don't convert CLASS255 to ANY (#618) 2018-01-07 17:57:04 +00:00
version.go Release 1.0.13 2018-10-10 07:39:49 +01:00
version_test.go Add semver (#595) 2017-12-06 09:46:54 +00:00
xfr.go TSIG name must be presented in canonical form (#574) 2017-11-17 13:17:47 +00:00
zcompress.go Remove compression from AFSDB (#704) 2018-06-23 09:43:19 +01:00
zduplicate.go Add IsDuplicate function (#699) 2018-06-23 09:12:31 +01:00
zmsg.go Remove compression from AFSDB (#704) 2018-06-23 09:43:19 +01:00
ztypes.go copyHeader is redundant (#672) 2018-05-10 14:50:26 +01:00

README.md

Build Status Code Coverage Go Report Card

Alternative (more granular) approach to a DNS library

Less is more.

Complete and usable DNS library. All widely used Resource Records are supported, including the DNSSEC types. It follows a lean and mean philosophy. If there is stuff you should know as a DNS programmer there isn't a convenience function for it. Server side and client side programming is supported, i.e. you can build servers and resolvers with it.

We try to keep the "master" branch as sane as possible and at the bleeding edge of standards, avoiding breaking changes wherever reasonable. We support the last two versions of Go.

Goals

  • KISS;
  • Fast;
  • Small API. If it's easy to code in Go, don't make a function for it.

Users

A not-so-up-to-date-list-that-may-be-actually-current:

Send pull request if you want to be listed here.

Features

  • UDP/TCP queries, IPv4 and IPv6;
  • RFC 1035 zone file parsing ($INCLUDE, $ORIGIN, $TTL and $GENERATE (for all record types) are supported;
  • Fast:
    • Reply speed around ~ 80K qps (faster hardware results in more qps);
    • Parsing RRs ~ 100K RR/s, that's 5M records in about 50 seconds;
  • Server side programming (mimicking the net/http package);
  • Client side programming;
  • DNSSEC: signing, validating and key generation for DSA, RSA, ECDSA and Ed25519;
  • EDNS0, NSID, Cookies;
  • AXFR/IXFR;
  • TSIG, SIG(0);
  • DNS over TLS: optional encrypted connection between client and server;
  • DNS name compression;
  • Depends only on the standard library.

Have fun!

Miek Gieben - 2010-2012 - miek@miek.nl

Building

Building is done with the go tool. If you have setup your GOPATH correctly, the following should work:

go get github.com/miekg/dns
go build github.com/miekg/dns

Examples

A short "how to use the API" is at the beginning of doc.go (this also will show when you call godoc github.com/miekg/dns).

Example programs can be found in the github.com/miekg/exdns repository.

Supported RFCs

all of them

  • 103{4,5} - DNS standard
  • 1348 - NSAP record (removed the record)
  • 1982 - Serial Arithmetic
  • 1876 - LOC record
  • 1995 - IXFR
  • 1996 - DNS notify
  • 2136 - DNS Update (dynamic updates)
  • 2181 - RRset definition - there is no RRset type though, just []RR
  • 2537 - RSAMD5 DNS keys
  • 2065 - DNSSEC (updated in later RFCs)
  • 2671 - EDNS record
  • 2782 - SRV record
  • 2845 - TSIG record
  • 2915 - NAPTR record
  • 2929 - DNS IANA Considerations
  • 3110 - RSASHA1 DNS keys
  • 3225 - DO bit (DNSSEC OK)
  • 340{1,2,3} - NAPTR record
  • 3445 - Limiting the scope of (DNS)KEY
  • 3597 - Unknown RRs
  • 403{3,4,5} - DNSSEC + validation functions
  • 4255 - SSHFP record
  • 4343 - Case insensitivity
  • 4408 - SPF record
  • 4509 - SHA256 Hash in DS
  • 4592 - Wildcards in the DNS
  • 4635 - HMAC SHA TSIG
  • 4701 - DHCID
  • 4892 - id.server
  • 5001 - NSID
  • 5155 - NSEC3 record
  • 5205 - HIP record
  • 5702 - SHA2 in the DNS
  • 5936 - AXFR
  • 5966 - TCP implementation recommendations
  • 6605 - ECDSA
  • 6725 - IANA Registry Update
  • 6742 - ILNP DNS
  • 6840 - Clarifications and Implementation Notes for DNS Security
  • 6844 - CAA record
  • 6891 - EDNS0 update
  • 6895 - DNS IANA considerations
  • 6975 - Algorithm Understanding in DNSSEC
  • 7043 - EUI48/EUI64 records
  • 7314 - DNS (EDNS) EXPIRE Option
  • 7477 - CSYNC RR
  • 7828 - edns-tcp-keepalive EDNS0 Option
  • 7553 - URI record
  • 7858 - DNS over TLS: Initiation and Performance Considerations
  • 7871 - EDNS0 Client Subnet
  • 7873 - Domain Name System (DNS) Cookies (draft-ietf-dnsop-cookies)
  • 8080 - EdDSA for DNSSEC

Loosely based upon

  • ldns
  • NSD
  • Net::DNS
  • GRONG