net/dns/resolver: have quad100 respond to suffix-less magicdns requests

This is an attempt to fix WSL2.

Unfortunately, it doesn't work in our new fancy split-dns mode.
If we went back to overriding all DNS on windows we could fix this.
This commit is contained in:
David Crawshaw 2021-06-12 08:44:02 -07:00
parent 525eb5ce41
commit 30550fc539
2 changed files with 27 additions and 5 deletions

View File

@ -236,8 +236,26 @@ func (r *Resolver) resolveLocal(domain dnsname.FQDN, typ dns.Type) (netaddr.IP,
return netaddr.IP{}, dns.RCodeNameError
}
}
// Not authoritative, signal that forwarding is advisable.
return netaddr.IP{}, dns.RCodeRefused
if strings.IndexByte(string(domain), '.') != len(domain)-1 {
// This is a real domain lookup.
// Not authoritative, signal that forwarding is advisable.
return netaddr.IP{}, dns.RCodeRefused
}
// Consider this as a MagicDNS query put directly to us.
var magicDNSDomain dnsname.FQDN
for _, suffix := range localDomains {
if dnsname.FQDN("tailscale.net.").Contains(suffix) || dnsname.FQDN("ts.net.").Contains(suffix) {
magicDNSDomain = suffix
break
}
}
if magicDNSDomain != "" {
addrs, found = hosts[domain+magicDNSDomain]
}
if !found {
// Not authoritative, signal that forwarding is advisable.
return netaddr.IP{}, dns.RCodeRefused
}
}
// Refactoring note: this must happen after we check suffixes,

View File

@ -20,13 +20,15 @@ import (
var testipv4 = netaddr.MustParseIP("1.2.3.4")
var testipv6 = netaddr.MustParseIP("0001:0203:0405:0607:0809:0a0b:0c0d:0e0f")
var test3ipv4 = netaddr.MustParseIP("1.2.4.5")
var dnsCfg = Config{
Hosts: map[dnsname.FQDN][]netaddr.IP{
"test1.ipn.dev.": []netaddr.IP{testipv4},
"test2.ipn.dev.": []netaddr.IP{testipv6},
"test1.ipn.dev.": []netaddr.IP{testipv4},
"test2.ipn.dev.": []netaddr.IP{testipv6},
"test3.mytailnet.ts.net.": []netaddr.IP{test3ipv4},
},
LocalDomains: []dnsname.FQDN{"ipn.dev."},
LocalDomains: []dnsname.FQDN{"mytailnet.ts.net.", "ipn.dev."},
}
func dnspacket(domain dnsname.FQDN, tp dns.Type) []byte {
@ -234,6 +236,8 @@ func TestResolveLocal(t *testing.T) {
{"mx-nxdomain", "test3.ipn.dev.", dns.TypeMX, netaddr.IP{}, dns.RCodeNameError},
{"ns-nxdomain", "test3.ipn.dev.", dns.TypeNS, netaddr.IP{}, dns.RCodeNameError},
{"onion-domain", "footest.onion.", dns.TypeA, netaddr.IP{}, dns.RCodeNameError},
{"magic", "test3.", dns.TypeA, test3ipv4, dns.RCodeSuccess},
{"nomagic", "test1.", dns.TypeA, netaddr.IP{}, dns.RCodeRefused},
}
for _, tt := range tests {