Mirrors/coredns
1
0
Fork 0
mirror of https://github.com/coredns/coredns.git synced 2025-12-06 10:25:10 -05:00
Code Issues Packages Projects Releases Wiki Activity

Fix EDNS0 compliance (#2357)

Browse Source 
* Fix EDNS0 compliance

Do SizeAndDo in the server (ScrubWriter) and remove all uses of this
from the plugins. Also *always* do it. This is to get into compliance
for https://dnsflagday.net/.

The pkg/edns0 now exports the EDNS0 options we understand; this is
exported to allow plugins add things there. The *rewrite* plugin used
this to add custom EDNS0 option codes that the server needs to
understand.

This also needs a new release of miekg/dns because it triggered a
race-condition that was basicly there forever.

See:
* https://github.com/miekg/dns/issues/857
* https://github.com/miekg/dns/pull/859

Running a test instance and pointing the https://ednscomp.isc.org/ednscomp
to it shows the tests are now fixed:

~~~
EDNS Compliance Tester
Checking: 'miek.nl' as at 2018-12-01T17:53:15Z

miek.nl. @147.75.204.203 (drone.coredns.io.): dns=ok edns=ok edns1=ok edns@512=ok ednsopt=ok edns1opt=ok do=ok ednsflags=ok docookie=ok edns512tcp=ok optlist=ok
miek.nl. @2604:1380:2002:a000::1 (drone.coredns.io.): dns=ok edns=ok edns1=ok edns@512=ok ednsopt=ok edns1opt=ok do=ok ednsflags=ok docookie=ok edns512tcp=ok optlist=ok

All Ok
Codes
ok - test passed.
~~~

Signed-off-by: Miek Gieben <miek@miek.nl>

Signed-off-by: Miek Gieben <miek@miek.nl>

* typos in comments

Signed-off-by: Miek Gieben <miek@miek.nl>
This commit is contained in:
Miek Gieben
2018-12-06 21:18:11 +00:00
committed by GitHub
parent f51c110511
commit fc667b98e0
16 changed files with 113 additions and 20 deletions
Download Patch File Download Diff File Expand all files Collapse all files

31
request/edns0.go Normal file
View File

@@ -0,0 +1,31 @@
package request
import (
"github.com/coredns/coredns/plugin/pkg/edns"
"github.com/miekg/dns"
)
func supportedOptions(o []dns.EDNS0) []dns.EDNS0 {
var supported = make([]dns.EDNS0, 0, 3)
// For as long as possible try avoid looking up in the map, because that need an Rlock.
for _, opt := range o {
switch code := opt.Option(); code {
case dns.EDNS0NSID:
fallthrough
case dns.EDNS0EXPIRE:
fallthrough
case dns.EDNS0COOKIE:
fallthrough
case dns.EDNS0TCPKEEPALIVE:
fallthrough
case dns.EDNS0PADDING:
supported = append(supported, opt)
default:
if edns.SupportedOption(code) {
supported = append(supported, opt)
}
}
}
return supported
}