dhcpd: assign random ip

dns/client.go

@@ -155,7 +155,7 @@ func (c *Client) exchange(qname string, reqBytes []byte, preferTCP bool) (
 		rc, err = dialer.Dial(network, server)
 		if err != nil {
 			newServer := ups.SwitchIf(server)
-			log.F("[dns] error in resolving %s, failed to connect to server %v via %s: %v, switch to %s",
+			log.F("[dns] error in resolving %s, failed to connect to server %v via %s: %v, next server: %s",
 				qname, server, dialer.Addr(), err, newServer)
 			server = newServer
 			continue
@@ -179,7 +179,7 @@ func (c *Client) exchange(qname string, reqBytes []byte, preferTCP bool) (
 		}
 
 		newServer := ups.SwitchIf(server)
-		log.F("[dns] error in resolving %s, failed to exchange with server %v via %s: %v, switch to %s",
+		log.F("[dns] error in resolving %s, failed to exchange with server %v via %s: %v, next server: %s",
 			qname, server, dialer.Addr(), err, newServer)
 
 		server = newServer

go.mod

@@ -13,7 +13,7 @@ require (
 	golang.org/x/crypto v0.0.0-20200820211705-5c72a883971a
 	golang.org/x/net v0.0.0-20200927032502-5d4f70055728 // indirect
 	golang.org/x/sys v0.0.0-20200926100807-9d91bd62050c // indirect
-	golang.org/x/tools v0.0.0-20200925191224-5d1fdd8fa346 // indirect
+	golang.org/x/tools v0.0.0-20200928112810-42b62fc93869 // indirect
 	gopkg.in/check.v1 v1.0.0-20200902074654-038fdea0a05b // indirect
 )
 

go.sum

@@ -173,8 +173,8 @@ golang.org/x/tools v0.0.0-20191119224855-298f0cb1881e/go.mod h1:b+2E5dAYhXwXZwtn
 golang.org/x/tools v0.0.0-20200425043458-8463f397d07c h1:iHhCR0b26amDCiiO+kBguKZom9aMF+NrFxh9zeKR/XU=
 golang.org/x/tools v0.0.0-20200425043458-8463f397d07c/go.mod h1:EkVYQZoAsY45+roYkvgYkIh4xh/qjgUK9TdY2XT94GE=
 golang.org/x/tools v0.0.0-20200808161706-5bf02b21f123/go.mod h1:njjCfa9FT2d7l9Bc6FUM5FLjQPp3cFF28FI3qnDFljA=
-golang.org/x/tools v0.0.0-20200925191224-5d1fdd8fa346 h1:hzJjkvxUIF3bSt+v8N5tBQNx/605vszZJ+3XsIamzZo=
+golang.org/x/tools v0.0.0-20200928112810-42b62fc93869 h1:6Zj8sAhgEtZaHYz4O/Grp2Gyh0FLb8a7sLJTanOG5QQ=
-golang.org/x/tools v0.0.0-20200925191224-5d1fdd8fa346/go.mod h1:z6u4i615ZeAfBE4XtMziQW1fSVJXACjjbWkB/mvPzlU=
+golang.org/x/tools v0.0.0-20200928112810-42b62fc93869/go.mod h1:z6u4i615ZeAfBE4XtMziQW1fSVJXACjjbWkB/mvPzlU=
 golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 golang.org/x/xerrors v0.0.0-20191011141410-1b5146add898/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543 h1:E7g+9GITq07hpfrRu66IVDexMakfv52eLZ2CXBWiKr4=

proxy/tcptun/tcptun.go

@@ -55,7 +55,7 @@ func NewTCPTunServer(s string, p proxy.Proxy) (proxy.Server, error) {
 func (s *TCPTun) ListenAndServe() {
 	l, err := net.Listen("tcp", s.addr)
 	if err != nil {
-		log.F("failed to listen on %s: %v", s.addr, err)
+		log.F("[tcptun] failed to listen on %s: %v", s.addr, err)
 		return
 	}
 

rule/forward.go

@@ -115,10 +115,13 @@ func (f *Forwarder) Failures() uint32 {
 // IncFailures increase the failuer count by 1.
 func (f *Forwarder) IncFailures() {
 	failures := atomic.AddUint32(&f.failures, 1)
+	if f.MaxFailures() == 0 {
+		return
+	}
+
 	log.F("[forwarder] %s recorded %d failures, maxfailures: %d", f.addr, failures, f.MaxFailures())
 
-	if f.MaxFailures() != 0 && failures >= f.MaxFailures() && f.Enabled() {
+	if failures >= f.MaxFailures() && f.Enabled() {
-		log.F("[forwarder] %s reaches maxfailures %d", f.addr, f.MaxFailures())
 		f.Disable()
 	}
 }

rule/group.go

@@ -271,7 +271,7 @@ func checkWebSite(fwdr *Forwarder, website string, timeout time.Duration, buf []
 	}
 
 	fwdr.Enable()
-	log.F("[check] %s(%d) -> %s, SUCCEEDED. connect time: %s", fwdr.Addr(), fwdr.Priority(),
+	log.F("[check] %s(%d) -> %s, SUCCESS. connect time: %s", fwdr.Addr(), fwdr.Priority(),
 		website, readTime)
 
 	return true

service/dhcpd/dhcpd.go

@@ -46,10 +46,10 @@ func (*dpcpd) Run(args ...string) {
 		return
 	}
 
-	server, err := server4.NewServer(
+	laddr := net.UDPAddr{IP: net.IPv4(0, 0, 0, 0), Port: 67}
-		iface, &net.UDPAddr{IP: net.IPv4(0, 0, 0, 0), Port: 67}, handleDHCP(ip, mask, pool))
+	server, err := server4.NewServer(iface, &laddr, handleDHCP(ip, mask, pool))
 	if err != nil {
-		log.F("[dhcpd] error in server new: %s", err)
+		log.F("[dhcpd] error in server creation: %s", err)
 		return
 	}
 
@@ -61,7 +61,7 @@ func (*dpcpd) Run(args ...string) {
 
 func handleDHCP(serverIP net.IP, mask net.IPMask, pool *Pool) server4.Handler {
 	return func(conn net.PacketConn, peer net.Addr, m *dhcpv4.DHCPv4) {
-		log.F("[dpcpd] received request from client %v", m.ClientHWAddr)
+		// log.F("[dpcpd] received request from client %v", m.ClientHWAddr)
 
 		var replyType dhcpv4.MessageType
 		switch mt := m.MessageType(); mt {
@@ -99,7 +99,7 @@ func handleDHCP(serverIP net.IP, mask net.IPMask, pool *Pool) server4.Handler {
 		}
 
 		if _, err := conn.WriteTo(reply.ToBytes(), peer); err != nil {
-			log.F("[dpcpd] could not write %v: %s", reply, err)
+			log.F("[dpcpd] could not write to client %s(%s): %s", peer, reply.ClientHWAddr, err)
 			return
 		}
 
@@ -136,20 +136,10 @@ func ifaceIPMask4(iface string) (net.IP, net.IPMask) {
 	}
 
 	for _, addr := range addrs {
-		var ip net.IP
+		if ipnet, ok := addr.(*net.IPNet); ok && !ipnet.IP.IsLoopback() {
-		var mask net.IPMask
+			if ip4 := ipnet.IP.To4(); ip4 != nil {
-
+				return ip4, ipnet.Mask
-		switch v := addr.(type) {
-		case *net.IPNet:
-			ip = v.IP
-			mask = v.Mask
-		case *net.IPAddr:
-			ip = v.IP
-			mask = ip.DefaultMask()
 			}
-
-		if ip4 := ip.To4(); ip4 != nil {
-			return ip4, mask
 		}
 	}
 

service/dhcpd/pool.go

@@ -3,38 +3,43 @@ package dhcpd
 import (
 	"bytes"
 	"errors"
+	"math/rand"
 	"net"
 	"time"
 )
 
 type Pool struct {
-	lease time.Duration
 	items []*item
 }
 
 func NewPool(lease time.Duration, ipStart, ipEnd net.IP) (*Pool, error) {
 	items := make([]*item, 0)
-	var currentIp = ipStart.To4()
+	curip := ipStart.To4()
-	for bytes.Compare(currentIp, ipEnd.To4()) <= 0 {
+	for bytes.Compare(curip, ipEnd.To4()) <= 0 {
 		ip := make([]byte, 4)
-		copy(ip, currentIp)
+		copy(ip, curip)
-		i := &item{
+		items = append(items, &item{lease: lease, ip: ip})
-			lease: lease,
+		curip[3]++
-			ip:    ip,
 	}
-		items = append(items, i)
+	rand.Seed(time.Now().Unix())
-		currentIp[3]++
+	return &Pool{items: items}, nil
-	}
-	return &Pool{lease: lease, items: items}, nil
 }
 
 func (p *Pool) AssignIP(mac net.HardwareAddr) (net.IP, error) {
 	var ip net.IP
 	for _, item := range p.items {
-		if mac.String() == item.hardwareAddr.String() {
+		if bytes.Equal(mac, item.mac) {
 			return item.ip, nil
 		}
 	}
+
+	idx := rand.Intn(len(p.items))
+	for _, item := range p.items[idx:] {
+		if ip = item.take(mac); ip != nil {
+			return ip, nil
+		}
+	}
+
 	for _, item := range p.items {
 		if ip = item.take(mac); ip != nil {
 			return ip, nil
@@ -44,24 +49,23 @@ func (p *Pool) AssignIP(mac net.HardwareAddr) (net.IP, error) {
 }
 
 type item struct {
+	taken bool
 	ip    net.IP
 	lease time.Duration
-	taken        bool
+	mac   net.HardwareAddr
-	hardwareAddr net.HardwareAddr
 }
 
 func (i *item) take(addr net.HardwareAddr) net.IP {
-	if i.taken {
+	if !i.taken {
-		return nil
-	} else {
 		i.taken = true
 		go func() {
 			timer := time.NewTimer(i.lease)
 			<-timer.C
-			i.hardwareAddr = nil
+			i.mac = nil
 			i.taken = false
 		}()
-		i.hardwareAddr = addr
+		i.mac = addr
 		return i.ip
 	}
+	return nil
 }