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Fix DNS responders when for non A and AAAA questions

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This commit is contained in:
Daniel 2020-10-15 11:32:19 +02:00
parent 3818718180
commit 3ded87fc2c
1 changed files with 18 additions and 9 deletions
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27
nameserver/nsutil/nsutil.go
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@ -10,6 +10,11 @@ import (
"github.com/safing/portbase/log"
)
var (
// ErrNilRR is returned when a parsed RR is nil.
ErrNilRR = errors.New("is nil")
)
// Responder defines the interface that any block/deny reason interface
// may implement to support sending custom DNS responses for a given reason.
// That is, if a reason context implements the Responder interface the
@ -39,8 +44,9 @@ func (rf ResponderFunc) ReplyWithDNS(ctx context.Context, request *dns.Msg) *dns
return rf(ctx, request)
}
// ZeroIP is a ResponderFunc than replies with either 0.0.0.0 or :: for
// each A or AAAA question respectively.
// ZeroIP is a ResponderFunc than replies with either 0.0.0.0 or :: for each A
// or AAAA question respectively. If there is no A or AAAA question, it
// defaults to replying with NXDomain.
func ZeroIP(msgs ...string) ResponderFunc {
return func(ctx context.Context, request *dns.Msg) *dns.Msg {
reply := new(dns.Msg)
@ -52,15 +58,16 @@ func ZeroIP(msgs ...string) ResponderFunc {
switch question.Qtype {
case dns.TypeA:
rr, err = dns.NewRR(question.Name + " 0 IN A 0.0.0.0")
rr, err = dns.NewRR(question.Name + " 0 IN A 0.0.0.0")
case dns.TypeAAAA:
rr, err = dns.NewRR(question.Name + " 0 IN AAAA ::")
rr, err = dns.NewRR(question.Name + " 0 IN AAAA ::")
}
if err != nil {
switch {
case err != nil:
log.Tracer(ctx).Errorf("nameserver: failed to create zero-ip response for %s: %s", question.Name, err)
hasErr = true
} else {
case rr != nil:
reply.Answer = append(reply.Answer, rr)
}
}
@ -81,6 +88,7 @@ func ZeroIP(msgs ...string) ResponderFunc {
}
// Localhost is a ResponderFunc than replies with localhost IP addresses.
// If there is no A or AAAA question, it defaults to replying with NXDomain.
func Localhost(msgs ...string) ResponderFunc {
return func(ctx context.Context, request *dns.Msg) *dns.Msg {
reply := new(dns.Msg)
@ -97,10 +105,11 @@ func Localhost(msgs ...string) ResponderFunc {
rr, err = dns.NewRR("localhost. 0 IN AAAA ::1")
}
if err != nil {
switch {
case err != nil:
log.Tracer(ctx).Errorf("nameserver: failed to create localhost response for %s: %s", question.Name, err)
hasErr = true
} else {
case rr != nil:
reply.Answer = append(reply.Answer, rr)
}
}
@ -159,7 +168,7 @@ func MakeMessageRecord(level log.Severity, msg string) (dns.RR, error) { //nolin
return nil, err
}
if rr == nil {
return nil, errors.New("record is nil")
return nil, ErrNilRR
}
return rr, nil
}