Add a runWithContext method

README.md

@@ -1,5 +1,4 @@
 # MTR
-[![Build Status](https://travis-ci.org/tonobo/mtr.svg?branch=master)](https://travis-ci.org/tonobo/mtr)
 
 A MTR implementation written in golang, completely without shell-execs.
 

cli/cli.go

@@ -43,12 +43,15 @@ var RootCmd = &cobra.Command{
 			return err
 		}
 		if jsonFmt {
-			go func(ch chan struct{}) {
+			go func(ch <-chan struct{}) {
 				for {
-					<-ch
+					_, isOpen := <-ch
+					if !isOpen {
+						return
+					}
 				}
 			}(ch)
-			m.Run(ch, COUNT)
+			m.Run(COUNT)
 			s, err := pj.Marshal(m)
 			if err != nil {
 				return err
@@ -59,16 +62,19 @@ var RootCmd = &cobra.Command{
 		fmt.Println("Start:", time.Now())
 		tm.Clear()
 		mu := &sync.Mutex{}
-		go func(ch chan struct{}) {
+		go func(ch <-chan struct{}) {
 			for {
 				mu.Lock()
-				<-ch
+				_, isOpen := <-ch
+				if !isOpen {
+					mu.Unlock()
+					return
+				}
 				render(m)
 				mu.Unlock()
 			}
 		}(ch)
-		m.Run(ch, COUNT)
-		close(ch)
+		m.Run(COUNT)
 		mu.Lock()
 		render(m)
 		mu.Unlock()

go.mod

@@ -1,13 +1,16 @@
 module github.com/tonobo/mtr
 
+go 1.16
+
 require (
 	github.com/buger/goterm v0.0.0-20181115115552-c206103e1f37
 	github.com/fatih/color v1.7.0 // indirect
 	github.com/hokaccha/go-prettyjson v0.0.0-20180920040306-f579f869bbfe
+	github.com/inconshreveable/mousetrap v1.0.0 // indirect
 	github.com/mattn/go-colorable v0.1.0 // indirect
 	github.com/mattn/go-isatty v0.0.4 // indirect
 	github.com/spf13/cobra v0.0.3
 	github.com/spf13/pflag v1.0.3 // indirect
-	golang.org/x/net v0.0.0-20190213061140-3a22650c66bd
-	golang.org/x/sys v0.0.0-20190220154126-629670e5acc5 // indirect
+	golang.org/x/net v0.0.0-20201021035429-f5854403a974
+	golang.org/x/sys v0.0.0-20210119212857-b64e53b001e4 // indirect
 )

go.sum

@@ -4,6 +4,8 @@ github.com/fatih/color v1.7.0 h1:DkWD4oS2D8LGGgTQ6IvwJJXSL5Vp2ffcQg58nFV38Ys=
 github.com/fatih/color v1.7.0/go.mod h1:Zm6kSWBoL9eyXnKyktHP6abPY2pDugNf5KwzbycvMj4=
 github.com/hokaccha/go-prettyjson v0.0.0-20180920040306-f579f869bbfe h1:MCgzztuoH5LZNr9AkIaicIDvCfACu11KUCCZQnRHDC0=
 github.com/hokaccha/go-prettyjson v0.0.0-20180920040306-f579f869bbfe/go.mod h1:pFlLw2CfqZiIBOx6BuCeRLCrfxBJipTY0nIOF/VbGcI=
+github.com/inconshreveable/mousetrap v1.0.0 h1:Z8tu5sraLXCXIcARxBp/8cbvlwVa7Z1NHg9XEKhtSvM=
+github.com/inconshreveable/mousetrap v1.0.0/go.mod h1:PxqpIevigyE2G7u3NXJIT2ANytuPF1OarO4DADm73n8=
 github.com/mattn/go-colorable v0.1.0 h1:v2XXALHHh6zHfYTJ+cSkwtyffnaOyR1MXaA91mTrb8o=
 github.com/mattn/go-colorable v0.1.0/go.mod h1:9vuHe8Xs5qXnSaW/c/ABM9alt+Vo+STaOChaDxuIBZU=
 github.com/mattn/go-isatty v0.0.4 h1:bnP0vzxcAdeI1zdubAl5PjU6zsERjGZb7raWodagDYs=
@@ -12,7 +14,16 @@ github.com/spf13/cobra v0.0.3 h1:ZlrZ4XsMRm04Fr5pSFxBgfND2EBVa1nLpiy1stUsX/8=
 github.com/spf13/cobra v0.0.3/go.mod h1:1l0Ry5zgKvJasoi3XT1TypsSe7PqH0Sj9dhYf7v3XqQ=
 github.com/spf13/pflag v1.0.3 h1:zPAT6CGy6wXeQ7NtTnaTerfKOsV6V6F8agHXFiazDkg=
 github.com/spf13/pflag v1.0.3/go.mod h1:DYY7MBk1bdzusC3SYhjObp+wFpr4gzcvqqNjLnInEg4=
-golang.org/x/net v0.0.0-20190213061140-3a22650c66bd h1:HuTn7WObtcDo9uEEU7rEqL0jYthdXAmZ6PP+meazmaU=
-golang.org/x/net v0.0.0-20190213061140-3a22650c66bd/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
-golang.org/x/sys v0.0.0-20190220154126-629670e5acc5 h1:3Nsfe5Xa1wTt01QxlAFIY5j9ycDtS+d7mhvI8ZY5bn0=
-golang.org/x/sys v0.0.0-20190220154126-629670e5acc5/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
+golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
+golang.org/x/crypto v0.0.0-20200622213623-75b288015ac9/go.mod h1:LzIPMQfyMNhhGPhUkYOs5KpL4U8rLKemX1yGLhDgUto=
+golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
+golang.org/x/net v0.0.0-20201021035429-f5854403a974 h1:IX6qOQeG5uLjB/hjjwjedwfjND0hgjPMMyO1RoIXQNI=
+golang.org/x/net v0.0.0-20201021035429-f5854403a974/go.mod h1:sp8m0HH+o8qH0wwXwYZr8TS3Oi6o0r6Gce1SSxlDquU=
+golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
+golang.org/x/sys v0.0.0-20190412213103-97732733099d/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20200930185726-fdedc70b468f/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20210119212857-b64e53b001e4 h1:myAQVi0cGEoqQVR5POX+8RR2mrocKqNN1hmeMqhX27k=
+golang.org/x/sys v0.0.0-20210119212857-b64e53b001e4/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
+golang.org/x/text v0.3.3/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
+golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=

install.sh

@@ -339,7 +339,7 @@ End of functions from https://github.com/client9/shlib
 EOF
 
 PROJECT_NAME="mtr"
-OWNER=tonobo
+OWNER="tonobo"
 REPO="mtr"
 BINARY=mtr
 FORMAT=tar.gz

pkg/hop/hop.go

@@ -145,7 +145,7 @@ func (h *HopStatistic) Render(ptrLookup bool) {
 	l := fmt.Sprintf("%d", h.RingBufferSize)
 	gm.Printf("%3d:|-- %-20s  %5.1f%%  %4d  %6.1f  %6.1f  %6.1f  %6.1f  %"+l+"s\n",
 		h.TTL,
-		fmt.Sprintf("%.20s", h.lookupAddr(ptrLookup, 0)),
+		fmt.Sprintf("%.20s", h.LookupAddr(ptrLookup, 0)),
 		h.Loss(),
 		h.Sent,
 		h.Last.Elapsed.Seconds()*1000,
@@ -156,8 +156,11 @@ func (h *HopStatistic) Render(ptrLookup bool) {
 	)
 }
 
-func (h *HopStatistic) lookupAddr(ptrLookup bool, index int) string {
-	addr := "???"
+func (h *HopStatistic) LookupAddr(ptrLookup bool, index int) string {
+	if h.dnsCache == nil {
+		h.dnsCache = map[string]string{}
+	}
+	addr := ""
 	if h.Targets[index] != "" {
 		addr = h.Targets[index]
 		if ptrLookup {

pkg/icmp/icmp.go

@@ -155,15 +155,41 @@ func listenForSpecific6(conn *icmp.PacketConn, deadline time.Time, neededPeer st
 		}
 
 		if x.Type.(ipv6.ICMPType) == ipv6.ICMPTypeTimeExceeded {
-			body := x.Body.(*icmp.TimeExceeded).Data
-			x, _ := icmp.ParseMessage(ProtocolIPv6ICMP, body[40:])
-			switch x.Body.(type) {
+			msg, ok := x.Body.(*icmp.TimeExceeded)
+			if !ok { // this should never happen
+				continue
+			}
+
+			// Be defensive regarding the junk we might end up
+			// getting here. Make sure the ICMP packet contains. an
+			// IPv6 packet.
+			_, err := ipv6.ParseHeader(msg.Data)
+			if err != nil {
+				continue
+			}
+
+			echoPkt := msg.Data[ipv6.HeaderLen:]
+
+			icmpMsg, err := icmp.ParseMessage(ProtocolIPv6ICMP, echoPkt)
+			if err != nil {
+				// We cannot error out here because we
+				// don't know if this packet was the
+				// one we were expecting or the one we
+				// were expecting is still in flight.
+				//
+				// To make that decision we need to be
+				// able to parse the packet.
+				continue
+			}
+
+			switch body := icmpMsg.Body.(type) {
 			case *icmp.Echo:
-				echoBody := x.Body.(*icmp.Echo)
-				if echoBody.Seq == needSeq && echoBody.ID == id {
+				if body.Seq == needSeq && body.ID == id {
 					return peer.String(), []byte{}, nil
 				}
+
 				continue
+
 			default:
 				// ignore
 			}
@@ -206,22 +232,58 @@ func listenForSpecific4(conn *icmp.PacketConn, deadline time.Time, neededPeer st
 			continue
 		}
 
-		if typ, ok := x.Type.(ipv4.ICMPType); ok && typ.String() == "time exceeded" {
-			body := x.Body.(*icmp.TimeExceeded).Data
-
-			index := bytes.Index(body, sent[:4])
-			if index > 0 {
-				x, _ := icmp.ParseMessage(ProtocolICMP, body[index:])
-				switch x.Body.(type) {
-				case *icmp.Echo:
-					echoBody := x.Body.(*icmp.Echo)
-					if echoBody.Seq == needSeq && echoBody.ID == pid {
-						return peer.String(), []byte{}, nil
-					}
-					continue
-				default:
-					// ignore
+		if typ, ok := x.Type.(ipv4.ICMPType); ok && typ == ipv4.ICMPTypeTimeExceeded {
+			msg, ok := x.Body.(*icmp.TimeExceeded)
+			if !ok { // this should never happen
+				continue
+			}
+
+			// Be defensive regarding the junk we might end up
+			// getting here. Make sure the ICMP packet contains:
+			// 1. an IPv4 packet
+			hdr, err := ipv4.ParseHeader(msg.Data)
+			if err != nil {
+				continue
+			}
+
+			// 2. containing an ICMP packet
+			if hdr.Protocol != ProtocolICMP {
+				continue
+			}
+
+			// 3. with a length that makes sense
+			echoPkt := msg.Data[hdr.Len:]
+			if len(sent) < 4 || len(echoPkt) < 4 {
+				continue
+			}
+
+			// The echo packet should match what we sent.
+			if !bytes.Equal(sent[:4], echoPkt[:4]) {
+				continue
+			}
+
+			icmpMsg, err := icmp.ParseMessage(ProtocolICMP, echoPkt)
+			if err != nil {
+				// We cannot error out here because we
+				// don't know if this packet was the
+				// one we were expecting or the one we
+				// were expecting is still in flight.
+				//
+				// To make that decision we need to be
+				// able to parse the packet.
+				continue
+			}
+
+			switch body := icmpMsg.Body.(type) {
+			case *icmp.Echo:
+				if body.Seq == needSeq && body.ID == pid {
+					return peer.String(), []byte{}, nil
 				}
+
+				continue
+
+			default:
+				// ignore
 			}
 		}