From db1e9e2b0caa4e4ef9b6d92270f4fe876dd50793 Mon Sep 17 00:00:00 2001
From: tsosunchia <59512455+tsosunchia@users.noreply.github.com>
Date: Thu, 5 Oct 2023 06:42:04 +0800
Subject: [PATCH] =?UTF-8?q?v4=20mpls=E5=AE=9E=E8=A3=85=E6=98=BE=E7=A4=BA?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 printer/basic.go   |  4 ++++
 printer/printer.go |  4 ++++
 trace/icmp_ipv4.go | 25 ++++++++++++++++++++++---
 trace/trace.go     |  1 +
 4 files changed, 31 insertions(+), 3 deletions(-)

diff --git a/printer/basic.go b/printer/basic.go
index c6ae53a..79377e1 100644
--- a/printer/basic.go
+++ b/printer/basic.go
@@ -108,4 +108,8 @@ func applyLangSetting(h *trace.Hop) {
 			}
 		}
 	}
+
+	if len(h.MPLS) > 1 {
+		h.Hostname += " [MPLS: " + h.MPLS + "]"
+	}
 }
diff --git a/printer/printer.go b/printer/printer.go
index ad32f0c..49d19f3 100644
--- a/printer/printer.go
+++ b/printer/printer.go
@@ -47,6 +47,10 @@ func HopPrinter(h trace.Hop, info HopInfo) {
 		if h.Geo != nil {
 			txt += " " + formatIpGeoData(h.Address.String(), h.Geo)
 		}
+
+		if len(h.MPLS) > 1 {
+			txt += " [MPLS: " + h.MPLS + "]"
+		}
 		switch info {
 		case IXP:
 			fmt.Print(CYAN_PREFIX)
diff --git a/trace/icmp_ipv4.go b/trace/icmp_ipv4.go
index af5178b..029c380 100644
--- a/trace/icmp_ipv4.go
+++ b/trace/icmp_ipv4.go
@@ -175,6 +175,9 @@ func (t *ICMPTracer) listenICMP() {
 func (t *ICMPTracer) handleICMPMessage(msg ReceivedMessage, icmpType int8, data []byte, ttl int) {
 	t.inflightRequestRWLock.RLock()
 	defer t.inflightRequestRWLock.RUnlock()
+	label, err := int64(0), error(nil)
+	tc, s, ttlMpls := int64(0), "", int64(0)
+	mpls := ""
 
 	extensionOffset := 20 + 8 + 52
 
@@ -185,12 +188,27 @@ func (t *ICMPTracer) handleICMPMessage(msg ReceivedMessage, icmpType int8, data
 			//log.Println("ICMP Multi-Part Extensions detected for TTL:", ttl)
 			//这里感觉会有问题，能力所限先这样吧，等有缘人来改
 			tmp := fmt.Sprintf("%x", msg.Msg[:*msg.N])
-			substring := tmp[len(tmp)-7 : len(tmp)-3]
-			label, err := strconv.ParseInt(substring, 16, 32)
+			substring := tmp[len(tmp)-8 : len(tmp)-3]
+			label, err = strconv.ParseInt(substring, 16, 32)
 			if err != nil {
 				return
 			}
-			log.Printf("MPLS for TTL %d: Lbl %d\n", ttl, label)
+			strSlice := []byte(tmp[len(tmp)-3 : len(tmp)-2])
+			charValue := int(strSlice[0] - '0')
+			binaryStr := fmt.Sprintf("%04b", charValue)
+			tc, err = strconv.ParseInt(binaryStr[:3], 2, 32)
+			if err != nil {
+				return
+			}
+			s = binaryStr[3:]
+
+			substring = tmp[len(tmp)-2:]
+			ttlMpls, err = strconv.ParseInt(substring, 16, 32)
+			if err != nil {
+				return
+			}
+			//fmt.Printf("MPLS for TTL %d: Lbl %d, TC %d, S %s, TTL %d\n", ttl, label, tc, s, ttlMpls)
+			mpls = fmt.Sprintf("Lbl %d, TC %d, S %s, TTL %d", label, tc, s, ttlMpls)
 		}
 	}
 
@@ -198,6 +216,7 @@ func (t *ICMPTracer) handleICMPMessage(msg ReceivedMessage, icmpType int8, data
 		t.inflightRequest[ttl] <- Hop{
 			Success: true,
 			Address: msg.Peer,
+			MPLS:    mpls,
 		}
 	}
 }
diff --git a/trace/trace.go b/trace/trace.go
index 2b552b3..f52ad7a 100644
--- a/trace/trace.go
+++ b/trace/trace.go
@@ -124,6 +124,7 @@ type Hop struct {
 	Error    error
 	Geo      *ipgeo.IPGeoData
 	Lang     string
+	MPLS     string
 }
 
 func (h *Hop) fetchIPData(c Config) (err error) {