fix: latency comparison had potential arithmetic overflow problem

component/outbound/dialer/alive_dialer_set.go

@@ -6,9 +6,11 @@
 package dialer
 
 import (
+	"fmt"
 	"github.com/mzz2017/softwind/pkg/fastrand"
 	"github.com/sirupsen/logrus"
 	"github.com/v2rayA/dae/common/consts"
+	"strings"
 	"sync"
 	"time"
 )
@@ -87,6 +89,19 @@ func (a *AliveDialerSet) GetMinLatency() (d *Dialer, latency time.Duration) {
 	return a.minLatency.dialer, a.minLatency.latency
 }
 
+func (a *AliveDialerSet) printLatencies() {
+	var builder strings.Builder
+	builder.WriteString(fmt.Sprintf("%v (%v):\n", a.dialerGroupName, a.CheckTyp.String()))
+	for _, d := range a.inorderedAliveDialerSet {
+		latency, ok := a.dialerToLatency[d]
+		if !ok {
+			continue
+		}
+		builder.WriteString(fmt.Sprintf("%v: %v\n", d.Name(), latency.String()))
+	}
+	a.log.Traceln(builder.String())
+}
+
 // NotifyLatencyChange should be invoked when dialer every time latency and alive state changes.
 func (a *AliveDialerSet) NotifyLatencyChange(dialer *Dialer, alive bool) {
 	a.mu.Lock()
@@ -146,7 +161,9 @@ func (a *AliveDialerSet) NotifyLatencyChange(dialer *Dialer, alive bool) {
 		bakOldBestDialer := a.minLatency.dialer
 		// Calc minLatency.
 		a.dialerToLatency[dialer] = latency
-		if alive && latency <= a.minLatency.latency-a.tolerance {
+		if alive &&
+			latency <= a.minLatency.latency && // To avoid arithmetic overflow.
+			latency <= a.minLatency.latency-a.tolerance {
 			a.minLatency.latency = latency
 			a.minLatency.dialer = dialer
 		} else if a.minLatency.dialer == dialer {
@@ -189,6 +206,9 @@ func (a *AliveDialerSet) NotifyLatencyChange(dialer *Dialer, alive bool) {
 					"network": a.CheckTyp.String(),
 				}).Infof("Group has no dialer alive")
 			}
+			if a.log.IsLevelEnabled(logrus.TraceLevel) {
+				a.printLatencies()
+			}
 		}
 	} else {
 		if alive && minPolicy && a.minLatency.dialer == nil {
@@ -219,7 +239,9 @@ func (a *AliveDialerSet) calcMinLatency() {
 	if a.minLatency.dialer == nil {
 		a.minLatency.latency = minLatency
 		a.minLatency.dialer = minDialer
-	} else if minDialer != nil && minLatency <= a.minLatency.latency-a.tolerance {
+	} else if minDialer != nil &&
+		minLatency <= a.minLatency.latency && // To avoid arithmetic overflow.
+		minLatency <= a.minLatency.latency-a.tolerance {
 		a.minLatency.latency = minLatency
 		a.minLatency.dialer = minDialer
 	}

control/tcp.go

@@ -73,6 +73,7 @@ func (c *ControlPlane) handleConn(lConn net.Conn) (err error) {
 	c.log.WithFields(logrus.Fields{
 		"network":  networkType.String(),
 		"outbound": outbound.Name,
+		"policy":   outbound.GetSelectionPolicy(),
 		"dialer":   d.Name(),
 	}).Infof("%v <-> %v", RefineSourceToShow(src, dst.Addr(), consts.LanWanFlag_NotApplicable), RefineAddrPortToShow(dst))
 	rConn, err := d.Dial("tcp", dst.String())

control/udp.go

@@ -309,7 +309,7 @@ func (c *ControlPlane) handlePkt(lConn *net.UDPConn, data []byte, src, pktDst, r
 			Target: destToSend,
 		})
 		if err != nil {
-			return fmt.Errorf("failed to GetOrCreate (%v): %w", outbound.GetSelectionPolicy(), err)
+			return fmt.Errorf("failed to GetOrCreate (policy: %v): %w", outbound.GetSelectionPolicy(), err)
 		}
 		// If the udp endpoint has been not alive, remove it from pool and get a new one.
 		if !isNew && !ue.Dialer.MustGetAlive(networkType) {
@@ -396,6 +396,7 @@ func (c *ControlPlane) handlePkt(lConn *net.UDPConn, data []byte, src, pktDst, r
 			c.log.WithFields(logrus.Fields{
 				"network":  string(l4proto) + string(ipversion) + "(DNS)",
 				"outbound": outbound.Name,
+				"policy":   outbound.GetSelectionPolicy(),
 				"dialer":   realDialer.Name(),
 				"qname":    strings.ToLower(q.Name.String()),
 				"qtype":    q.Type,
@@ -407,6 +408,7 @@ func (c *ControlPlane) handlePkt(lConn *net.UDPConn, data []byte, src, pktDst, r
 			c.log.WithFields(logrus.Fields{
 				"network":  string(l4proto) + string(ipversion),
 				"outbound": outbound.Name,
+				"policy":   outbound.GetSelectionPolicy(),
 				"dialer":   realDialer.Name(),
 			}).Infof("%v <-> %v",
 				RefineSourceToShow(realSrc, realDst.Addr(), lanWanFlag), RefineAddrPortToShow(destToSend),