miracle091/dnscrypt-proxy
miracle091
/
dnscrypt-proxy
mirror of https://github.com/DNSCrypt/dnscrypt-proxy.git
1
0
Fork 0
Code Issues Releases Wiki Activity

cloak: decrement TTL

This commit is contained in:
Frank Denis 2018-02-04 09:36:57 +01:00
parent d005a76dc4
commit cfeb25a4c2
1 changed files with 21 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

26
dnscrypt-proxy/plugin_cloak.go
View File

@ -23,6 +23,7 @@ type CloakedName struct {
type PluginCloak struct {
sync.RWMutex
cloakedNames map[string]*CloakedName
ttl uint32
}
func (plugin *PluginCloak) Name() string {
@ -39,6 +40,7 @@ func (plugin *PluginCloak) Init(proxy *Proxy) error {
if err != nil {
return err
}
plugin.ttl = proxy.cacheMinTTL
plugin.cloakedNames = make(map[string]*CloakedName)
for lineNo, line := range strings.Split(string(bin), "\n") {
line = strings.TrimFunc(line, unicode.IsSpace)
@ -99,18 +101,30 @@ func (plugin *PluginCloak) Eval(pluginsState *PluginsState, msg *dns.Msg) error
if len(qName) < 2 {
return nil
}
now := time.Now()
plugin.RLock()
cloakedName, _ := plugin.cloakedNames[qName]
plugin.RUnlock()
if cloakedName == nil {
plugin.RUnlock()
return nil
}
if cloakedName.ipv4 == nil && cloakedName.ipv6 == nil && !cloakedName.isIP {
foundIPs, err := net.LookupIP(cloakedName.target)
ttl, expired := plugin.ttl, false
if cloakedName.lastUpdate != nil {
if elapsed := uint32(now.Sub(*cloakedName.lastUpdate).Seconds()); elapsed < ttl {
ttl -= elapsed
} else {
expired = true
}
}
if !cloakedName.isIP && ((cloakedName.ipv4 == nil && cloakedName.ipv6 == nil) || expired) {
target := cloakedName.target
plugin.RUnlock()
foundIPs, err := net.LookupIP(target)
if err != nil {
return nil
}
plugin.Lock()
cloakedName.lastUpdate = &now
for _, foundIP := range foundIPs {
if ipv4 := foundIP.To4(); ipv4 != nil {
cloakedName.ipv4 = &ipv4
@ -122,6 +136,8 @@ func (plugin *PluginCloak) Eval(pluginsState *PluginsState, msg *dns.Msg) error
}
}
plugin.Unlock()
} else {
plugin.RUnlock()
}
var ip *net.IP
if question.Qtype == dns.TypeA {
@ -137,12 +153,12 @@ func (plugin *PluginCloak) Eval(pluginsState *PluginsState, msg *dns.Msg) error
synth.Answer = []dns.RR{}
} else if question.Qtype == dns.TypeA {
rr := new(dns.A)
rr.Hdr = dns.RR_Header{Name: question.Name, Rrtype: dns.TypeA, Class: dns.ClassINET, Ttl: 1}
rr.Hdr = dns.RR_Header{Name: question.Name, Rrtype: dns.TypeA, Class: dns.ClassINET, Ttl: ttl}
rr.A = *ip
synth.Answer = []dns.RR{rr}
} else {
rr := new(dns.AAAA)
rr.Hdr = dns.RR_Header{Name: question.Name, Rrtype: dns.TypeAAAA, Class: dns.ClassINET, Ttl: 1}
rr.Hdr = dns.RR_Header{Name: question.Name, Rrtype: dns.TypeAAAA, Class: dns.ClassINET, Ttl: ttl}
rr.AAAA = *ip
synth.Answer = []dns.RR{rr}
}