zabov/dns_handler.go

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package main
import (
"fmt"
"log"
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"net"
"os"
"path"
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"strings"
"time"
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"github.com/miekg/dns"
)
var reqTypes map[uint16]string
var weekdays []string
type logItem struct {
clientIP string
name string
reqType uint16
config string
timetable string
killed string
}
// logChannel used by logging thread
var logChannel chan logItem
func init() {
weekdays = []string{"Su", "Mo", "Tu", "We", "Th", "Fr", "Sa"}
if len(ZabovDebugDBPath) > 0 {
os.MkdirAll(ZabovDebugDBPath, 0755)
}
reqTypes = map[uint16]string{
dns.TypeNone: "TypeNone",
dns.TypeA: "TypeA",
dns.TypeNS: "TypeNS",
dns.TypeMD: "TypeMD",
dns.TypeMF: "TypeMF",
dns.TypeCNAME: "TypeCNAME",
dns.TypeSOA: "TypeSOA",
dns.TypeMB: "TypeMB",
dns.TypeMG: "TypeMG",
dns.TypeMR: "TypeMR",
dns.TypeNULL: "TypeNULL",
dns.TypePTR: "TypePTR",
dns.TypeHINFO: "TypeHINFO",
dns.TypeMINFO: "TypeMINFO",
dns.TypeMX: "TypeMX",
dns.TypeTXT: "TypeTXT",
dns.TypeRP: "TypeRP",
dns.TypeAFSDB: "TypeAFSDB",
dns.TypeX25: "TypeX25",
dns.TypeISDN: "TypeISDN",
dns.TypeRT: "TypeRT",
dns.TypeNSAPPTR: "TypeNSAPPTR",
dns.TypeSIG: "TypeSIG",
dns.TypeKEY: "TypeKEY",
dns.TypePX: "TypePX",
dns.TypeGPOS: "TypeGPOS",
dns.TypeAAAA: "TypeAAAA",
dns.TypeLOC: "TypeLOC",
dns.TypeNXT: "TypeNXT",
dns.TypeEID: "TypeEID",
dns.TypeNIMLOC: "TypeNIMLOC",
dns.TypeSRV: "TypeSRV",
dns.TypeATMA: "TypeATMA",
dns.TypeNAPTR: "TypeNAPTR",
dns.TypeKX: "TypeKX",
dns.TypeCERT: "TypeCERT",
dns.TypeDNAME: "TypeDNAME",
dns.TypeOPT: "TypeOPT",
dns.TypeAPL: "TypeAPL",
dns.TypeDS: "TypeDS",
dns.TypeSSHFP: "TypeSSHFP",
dns.TypeRRSIG: "TypeRRSIG",
dns.TypeNSEC: "TypeNSEC",
dns.TypeDNSKEY: "TypeDNSKEY",
dns.TypeDHCID: "TypeDHCID",
dns.TypeNSEC3: "TypeNSEC3",
dns.TypeNSEC3PARAM: "TypeNSEC3PARAM",
dns.TypeTLSA: "TypeTLSA",
dns.TypeSMIMEA: "TypeSMIMEA",
dns.TypeHIP: "TypeHIP",
dns.TypeNINFO: "TypeNINFO",
dns.TypeRKEY: "TypeRKEY",
dns.TypeTALINK: "TypeTALINK",
dns.TypeCDS: "TypeCDS",
dns.TypeCDNSKEY: "TypeCDNSKEY",
dns.TypeOPENPGPKEY: "TypeOPENPGPKEY",
dns.TypeCSYNC: "TypeCSYNC",
dns.TypeSPF: "TypeSPF",
dns.TypeUINFO: "TypeUINFO",
dns.TypeUID: "TypeUID",
dns.TypeGID: "TypeGID",
dns.TypeUNSPEC: "TypeUNSPEC",
dns.TypeNID: "TypeNID",
dns.TypeL32: "TypeL32",
dns.TypeL64: "TypeL64",
dns.TypeLP: "TypeLP",
dns.TypeEUI48: "TypeEUI48",
dns.TypeEUI64: "TypeEUI64",
dns.TypeURI: "TypeURI",
dns.TypeCAA: "TypeCAA",
dns.TypeAVC: "TypeAVC",
dns.TypeTKEY: "TypeTKEY",
dns.TypeTSIG: "TypeTSIG",
dns.TypeIXFR: "TypeIXFR",
dns.TypeAXFR: "TypeAXFR",
dns.TypeMAILB: "TypeMAILB",
dns.TypeMAILA: "TypeMAILA",
dns.TypeANY: "TypeANY",
dns.TypeTA: "TypeTA",
dns.TypeDLV: "TypeDLV",
dns.TypeReserved: "TypeReserved"}
fmt.Println("Local Time:", getLocalTime().Format(time.ANSIC))
if len(ZabovDebugDBPath) > 0 {
logChannel = make(chan logItem, 1024)
go logWriteThread()
}
}
func logWriteThread() {
for item := range logChannel {
var header string
d := time.Now().Format("2006-01-02")
logpath := path.Join(ZabovDebugDBPath, strings.Replace(item.clientIP, ":", "_", -1)+"-"+d+".log")
_, err1 := os.Stat(logpath)
if os.IsNotExist(err1) {
header = strings.Join([]string{"time", "clientIP", "name", "reqType", "config", "timetable", "killed"}, "\t")
}
f, err := os.OpenFile(logpath, os.O_APPEND|os.O_CREATE|os.O_WRONLY, 0644)
if err == nil {
reqTypeName, err := reqTypes[item.reqType]
if !err {
reqTypeName = fmt.Sprintf("%d", item.reqType)
}
ct := time.Now().Format(time.RFC3339)
log := strings.Join([]string{ct, item.clientIP, strings.TrimRight(item.name, "."), reqTypeName, item.config, item.timetable, item.killed}, "\t")
if len(header) > 0 {
f.Write([]byte(header))
f.Write([]byte("\n"))
}
f.Write([]byte(log))
f.Write([]byte("\n"))
f.Close()
}
}
}
func logQuery(clientIP string, name string, reqType uint16, config string, timetable string, killed string) {
if len(ZabovDebugDBPath) > 0 {
k := logItem{clientIP: clientIP, name: name, reqType: reqType, config: config, timetable: timetable, killed: killed}
logChannel <- k
}
}
func getLocalTime() time.Time {
return time.Now().Local()
}
func confFromTimeTable(timetable string) string {
tt := ZabovTimetables[timetable]
if tt == nil {
if ZabovDebug {
log.Println("confFromTimeTable: return default")
}
return "default"
}
for _, ttentry := range tt.table {
now := getLocalTime()
nowHour := now.Hour()
nowMinute := now.Minute()
weekday := weekdays[now.Weekday()]
if ttentry.days == nil || len(ttentry.days) == 0 || ttentry.days[weekday] || ttentry.days[strings.ToLower(weekday)] {
for _, t := range ttentry.times {
if (nowHour > t.start.hour || (nowHour == t.start.hour && nowMinute >= t.start.minute)) &&
(nowHour < t.stop.hour || (nowHour == t.stop.hour && nowMinute <= t.stop.minute)) {
go incrementStats("TIMETABLE IN: "+timetable, 1)
if ZabovDebug {
log.Println("confFromTimeTable: return IN", tt.cfgin)
}
return tt.cfgin
}
}
}
}
go incrementStats("TIMETABLE OUT: "+timetable, 1)
if ZabovDebug {
log.Println("confFromTimeTable: return OUT", tt.cfgout)
}
return tt.cfgout
}
func confFromIP(clientIP net.IP) (string, string) {
for _, ipgroup := range ZabovIPGroups {
for _, ip := range ipgroup.ips {
if clientIP.Equal(ip) {
if len(ipgroup.timetable) > 0 {
return confFromTimeTable(ipgroup.timetable), ipgroup.timetable
}
if ZabovDebug {
log.Println("confFromIP: ipgroup.cfg", ipgroup.cfg)
}
return ipgroup.cfg, ""
}
}
}
if len(ZabovDefaultTimetable) > 0 {
return confFromTimeTable(ZabovDefaultTimetable), ZabovDefaultTimetable
}
if ZabovDebug {
log.Println("confFromIP: return default")
}
return "default", ""
}
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func (mydns *handler) ServeDNS(w dns.ResponseWriter, r *dns.Msg) {
go incrementStats("TotalQueries", 1)
remIP, _, e := net.SplitHostPort(w.RemoteAddr().String())
if e != nil {
go incrementStats("CLIENT ERROR: "+remIP, 1)
} else {
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go incrementStats("CLIENT: "+remIP, 1)
}
msg := dns.Msg{}
msg.SetReply(r)
config, timetable := confFromIP(net.ParseIP(remIP))
if ZabovDebug {
log.Println("REQUEST:", remIP, config)
}
ZabovConfig := ZabovConfigs[config]
QType := r.Question[0].Qtype
switch QType {
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case dns.TypeA:
msg.Authoritative = true
domain := msg.Question[0].Name
fqdn := strings.TrimRight(domain, ".")
if ZabovDebug {
log.Println("TypeA: fqdn:", fqdn)
}
if len(ZabovIPAliases[fqdn]) > 0 {
config = "__aliases__"
msg.Answer = append(msg.Answer, &dns.A{
Hdr: dns.RR_Header{Name: domain, Rrtype: dns.TypeA, Class: dns.ClassINET, Ttl: 60},
A: net.ParseIP(ZabovIPAliases[fqdn]),
})
go logQuery(remIP, fqdn, QType, config, timetable, "alias")
break
}
if len(ZabovLocalResponder) > 0 {
if !strings.Contains(fqdn, ".") ||
(len(ZabovLocalDomain) > 0 && strings.HasSuffix(fqdn, ZabovLocalDomain)) {
config = "__localresponder__"
ret := ForwardQuery(r, config, true)
w.WriteMsg(ret)
go logQuery(remIP, fqdn, QType, config, timetable, "localresponder")
break
}
}
if domainInKillfile(fqdn, config) {
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go incrementStats("Killed", 1)
msg.Answer = append(msg.Answer, &dns.A{
Hdr: dns.RR_Header{Name: domain, Rrtype: dns.TypeA, Class: dns.ClassINET, Ttl: 60},
A: net.ParseIP(ZabovConfig.ZabovAddBL),
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})
go logQuery(remIP, fqdn, QType, config, timetable, "killed")
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} else {
go logQuery(remIP, fqdn, QType, config, timetable, "forwarded")
ret := ForwardQuery(r, config, false)
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w.WriteMsg(ret)
}
case dns.TypePTR:
if ZabovDebug {
log.Println("TypePTR: Name:", msg.Question[0].Name)
}
if len(ZabovLocalResponder) > 0 {
// if set use local responder for reverse lookup (suffix ".in-addr.arpa.")
config = "__localresponder__"
}
ret := ForwardQuery(r, config, true)
w.WriteMsg(ret)
go logQuery(remIP, msg.Question[0].Name, QType, config, timetable, "localresponder")
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default:
ret := ForwardQuery(r, config, false)
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w.WriteMsg(ret)
if len(ZabovDebugDBPath) > 0 {
go logQuery(remIP, msg.Question[0].Name, QType, config, timetable, "forwarded")
}
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}
go incrementStats("CONFIG: "+config, 1)
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w.WriteMsg(&msg)
}