a
/
badguardhome
1
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

coredns plugin -- Add option "blocked_ttl" that can change default nxdomain response TTL

This commit is contained in:
Eugene Bujak 2018-09-26 18:27:31 +03:00
parent c9e10c9de7
commit c7790a8d9f
2 changed files with 20 additions and 7 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
config.go
View File

@ -40,6 +40,7 @@ type coreDNSConfig struct {
SafeSearchEnabled bool `yaml:"safesearch_enabled"`
ParentalEnabled bool `yaml:"parental_enabled"`
ParentalSensitivity int `yaml:"parental_sensitivity"`
BlockedResponseTTL int `yaml:"blocked_response_ttl"`
QueryLogEnabled bool `yaml:"querylog_enabled"`
Pprof string `yaml:"-"`
Cache string `yaml:"-"`
@ -70,6 +71,7 @@ var config = configuration{
FilterFile: "dnsfilter.txt", // only filename, no path
FilteringEnabled: true,
SafeBrowsingEnabled: true,
BlockedResponseTTL: 60, // in seconds
QueryLogEnabled: true,
UpstreamDNS: defaultDNS,
Cache: "cache",

25
coredns_plugin/coredns_plugin.go
View File

@ -54,11 +54,13 @@ type plug struct {
SafeBrowsingBlockHost string
ParentalBlockHost string
QueryLogEnabled bool
BlockedTTL uint32 // in seconds, default 3600
}
var defaultPlugin = plug{
SafeBrowsingBlockHost: "safebrowsing.block.dns.adguard.com",
ParentalBlockHost: "family.block.dns.adguard.com",
BlockedTTL: 3600, // in seconds
}
func newDNSCounter(name string, help string) prometheus.Counter {
@ -128,6 +130,15 @@ func setupPlugin(c *caddy.Controller) (*plug, error) {
}
p.ParentalBlockHost = c.Val()
}
case "blocked_ttl":
if !c.NextArg() {
return nil, c.ArgErr()
}
blockttl, err := strconv.ParseUint(c.Val(), 10, 32)
if err != nil {
return nil, c.ArgErr()
}
p.BlockedTTL = uint32(blockttl)
case "querylog":
p.QueryLogEnabled = true
onceQueryLog.Do(func() {
@ -294,7 +305,7 @@ func (p *plug) replaceHostWithValAndReply(ctx context.Context, w dns.ResponseWri
log.Println("Will give", val, "instead of", host)
if addr != nil {
// this is an IP address, return it
result, err := dns.NewRR(host + " A " + val)
result, err := dns.NewRR(fmt.Sprintf("%s %d A %s", host, p.BlockedTTL, val))
if err != nil {
log.Printf("Got error %s\n", err)
return dns.RcodeServerFailure, fmt.Errorf("plugin/dnsfilter: %s", err)
@ -334,9 +345,9 @@ func (p *plug) replaceHostWithValAndReply(ctx context.Context, w dns.ResponseWri
// generate SOA record that makes DNS clients cache NXdomain results
// the only value that is important is TTL in header, other values like refresh, retry, expire and minttl are irrelevant
func genSOA(r *dns.Msg) []dns.RR {
func (p *plug) genSOA(r *dns.Msg) []dns.RR {
zone := r.Question[0].Name
header := dns.RR_Header{Name: zone, Rrtype: dns.TypeSOA, Ttl: 3600, Class: dns.ClassINET}
header := dns.RR_Header{Name: zone, Rrtype: dns.TypeSOA, Ttl: p.BlockedTTL, Class: dns.ClassINET}
Mbox := "hostmaster."
if zone[0] != '.' {
@ -352,12 +363,12 @@ func genSOA(r *dns.Msg) []dns.RR {
return []dns.RR{soa}
}
func writeNXdomain(ctx context.Context, w dns.ResponseWriter, r *dns.Msg) (int, error) {
func (p *plug) writeNXdomain(ctx context.Context, w dns.ResponseWriter, r *dns.Msg) (int, error) {
state := request.Request{W: w, Req: r, Context: ctx}
m := new(dns.Msg)
m.SetRcode(state.Req, dns.RcodeNameError)
m.Authoritative, m.RecursionAvailable, m.Compress = true, true, true
m.Ns = genSOA(r)
m.Ns = p.genSOA(r)
state.SizeAndDo(m)
err := state.W.WriteMsg(m)
@ -389,7 +400,7 @@ func (p *plug) serveDNSInternal(ctx context.Context, w dns.ResponseWriter, r *dn
// it is, if it's a loopback host, reply with NXDOMAIN
// TODO: research if it's better than 127.0.0.1
if false && val.IsLoopback() {
rcode, err := writeNXdomain(ctx, w, r)
rcode, err := p.writeNXdomain(ctx, w, r)
if err != nil {
return rcode, dnsfilter.Result{}, err
}
@ -430,7 +441,7 @@ func (p *plug) serveDNSInternal(ctx context.Context, w dns.ResponseWriter, r *dn
return rcode, result, err
case dnsfilter.FilteredBlackList:
// return NXdomain
rcode, err := writeNXdomain(ctx, w, r)
rcode, err := p.writeNXdomain(ctx, w, r)
if err != nil {
return rcode, dnsfilter.Result{}, err
}