From a539a4e079f830cdd4fc0198fa468001c5f595fc Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E6=96=B9=E9=B8=BB?= <zhufengyu.zfy@alibaba-inc.com>
Date: Fri, 12 Jul 2024 17:53:55 +0800
Subject: [PATCH] fix(trace): limit channel buffer size in TCP and UDP tracing
 to avoid deadlock

---
 trace/tcp_ipv4.go | 2 +-
 trace/tcp_ipv6.go | 2 +-
 trace/udp.go      | 2 +-
 3 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/trace/tcp_ipv4.go b/trace/tcp_ipv4.go
index 4bf1c29..01e27c5 100644
--- a/trace/tcp_ipv4.go
+++ b/trace/tcp_ipv4.go
@@ -264,7 +264,7 @@ func (t *TCPTracer) send(ttl int) error {
 		return err
 	}
 	t.inflightRequestLock.Lock()
-	hopCh := make(chan Hop)
+	hopCh := make(chan Hop, 1)
 	t.inflightRequest[int(sequenceNumber)] = hopCh
 	t.inflightRequestLock.Unlock()
 	/*
diff --git a/trace/tcp_ipv6.go b/trace/tcp_ipv6.go
index 801d1c9..f622a41 100644
--- a/trace/tcp_ipv6.go
+++ b/trace/tcp_ipv6.go
@@ -251,7 +251,7 @@ func (t *TCPTracerv6) send(ttl int) error {
 	}
 	// log.Println(ttl, sequenceNumber)
 	t.inflightRequestLock.Lock()
-	hopCh := make(chan Hop)
+	hopCh := make(chan Hop, 1)
 	t.inflightRequest[int(sequenceNumber)] = hopCh
 	t.inflightRequestLock.Unlock()
 
diff --git a/trace/udp.go b/trace/udp.go
index 3f68401..e968ca1 100644
--- a/trace/udp.go
+++ b/trace/udp.go
@@ -225,7 +225,7 @@ func (t *UDPTracer) send(ttl int) error {
 
 	// 在对inflightRequest进行写操作的时候应该加锁保护，以免多个goroutine协程试图同时写入造成panic
 	t.inflightRequestLock.Lock()
-	hopCh := make(chan Hop)
+	hopCh := make(chan Hop, 1)
 	t.inflightRequest[srcPort] = hopCh
 	t.inflightRequestLock.Unlock()
 	defer func() {