community
/
dns
3
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Fix EDNS0_SUBNET compatibility with dig (#530) 

Do not complain about AddressFamily=0, if SubnetNetmask is also 0.

Fixes issue #529
This commit is contained in:
Star Brilliant 2017-10-14 00:04:01 +08:00 committed by Miek Gieben
parent 6f3c0a126c
commit f218fef126
1 changed files with 13 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

13
edns.go
View File

@ -229,6 +229,12 @@ func (e *EDNS0_SUBNET) pack() ([]byte, error) {
b[2] = e.SourceNetmask
b[3] = e.SourceScope
switch e.Family {
case 0:
// "dig" sets AddressFamily to 0 if SourceNetmask is also 0
// We might don't need to complain either
if e.SourceNetmask != 0 {
return nil, errors.New("dns: bad address family")
}
case 1:
if e.SourceNetmask > net.IPv4len*8 {
return nil, errors.New("dns: bad netmask")
@ -263,6 +269,13 @@ func (e *EDNS0_SUBNET) unpack(b []byte) error {
e.SourceNetmask = b[2]
e.SourceScope = b[3]
switch e.Family {
case 0:
// "dig" sets AddressFamily to 0 if SourceNetmask is also 0
// It's okay to accept such a packet
if e.SourceNetmask != 0 {
return errors.New("dns: bad address family")
}
e.Address = net.IPv4(0, 0, 0, 0)
case 1:
if e.SourceNetmask > net.IPv4len*8 || e.SourceScope > net.IPv4len*8 {
return errors.New("dns: bad netmask")