TrueCloudLab/coredns
16
0
Fork 2
Code Issues Pull requests 1 Projects Releases Packages Wiki Activity Actions

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
No known key found for this signature in database
GPG key ID: 4AEE18F83AFDEB23
16 changed files with 113 additions and 20 deletions
Download patch file Download diff file Expand all files Collapse all files

9
plugin/rewrite/edns0.go
View file

@ -10,6 +10,7 @@ import (
"strings"
"github.com/coredns/coredns/plugin/metadata"
"github.com/coredns/coredns/plugin/pkg/edns"
"github.com/coredns/coredns/request"
"github.com/miekg/dns"
@ -159,6 +160,10 @@ func newEdns0LocalRule(mode, action, code, data string) (*edns0LocalRule, error)
return nil, err
}
}
// Add this code to the ones the server supports.
edns.SetSupportedOption(uint16(c))
return &edns0LocalRule{mode: mode, action: action, code: uint16(c), data: decoded}, nil
}
@ -172,6 +177,10 @@ func newEdns0VariableRule(mode, action, code, variable string) (*edns0VariableRu
if !isValidVariable(variable) {
return nil, fmt.Errorf("unsupported variable name %q", variable)
}
// Add this code to the ones the server supports.
edns.SetSupportedOption(uint16(c))
return &edns0VariableRule{mode: mode, action: action, code: uint16(c), variable: variable}, nil
}