clash/dns/util.go

107 lines
2.1 KiB
Go

package dns
import (
"crypto/tls"
"net"
"time"
"github.com/Dreamacro/clash/common/cache"
"github.com/Dreamacro/clash/log"
D "github.com/miekg/dns"
)
func putMsgToCache(c *cache.LruCache, key string, msg *D.Msg) {
var ttl uint32
switch {
case len(msg.Answer) != 0:
ttl = msg.Answer[0].Header().Ttl
case len(msg.Ns) != 0:
ttl = msg.Ns[0].Header().Ttl
case len(msg.Extra) != 0:
ttl = msg.Extra[0].Header().Ttl
default:
log.Debugln("[DNS] response msg empty: %#v", msg)
return
}
c.SetWithExpire(key, msg.Copy(), time.Now().Add(time.Second*time.Duration(ttl)))
}
func setMsgTTL(msg *D.Msg, ttl uint32) {
for _, answer := range msg.Answer {
answer.Header().Ttl = ttl
}
for _, ns := range msg.Ns {
ns.Header().Ttl = ttl
}
for _, extra := range msg.Extra {
extra.Header().Ttl = ttl
}
}
func isIPRequest(q D.Question) bool {
return q.Qclass == D.ClassINET && (q.Qtype == D.TypeA || q.Qtype == D.TypeAAAA)
}
func transform(servers []NameServer, resolver *Resolver) []dnsClient {
ret := []dnsClient{}
for _, s := range servers {
switch s.Net {
case "https":
ret = append(ret, newDoHClient(s.Addr, resolver))
continue
case "dhcp":
ret = append(ret, newDHCPClient(s.Addr))
continue
}
host, port, _ := net.SplitHostPort(s.Addr)
ret = append(ret, &client{
Client: &D.Client{
Net: s.Net,
TLSConfig: &tls.Config{
// alpn identifier, see https://tools.ietf.org/html/draft-hoffman-dprive-dns-tls-alpn-00#page-6
NextProtos: []string{"dns"},
ServerName: host,
},
UDPSize: 4096,
Timeout: 5 * time.Second,
},
port: port,
host: host,
iface: s.Interface,
r: resolver,
})
}
return ret
}
func handleMsgWithEmptyAnswer(r *D.Msg) *D.Msg {
msg := &D.Msg{}
msg.Answer = []D.RR{}
msg.SetRcode(r, D.RcodeSuccess)
msg.Authoritative = true
msg.RecursionAvailable = true
return msg
}
func msgToIP(msg *D.Msg) []net.IP {
ips := []net.IP{}
for _, answer := range msg.Answer {
switch ans := answer.(type) {
case *D.AAAA:
ips = append(ips, ans.AAAA)
case *D.A:
ips = append(ips, ans.A)
}
}
return ips
}