From 6b264e1c782c8fc529e9a08694d210f5ed8359bd Mon Sep 17 00:00:00 2001
From: Hugo Arregui <969314+hugoArregui@users.noreply.github.com>
Date: Thu, 29 Feb 2024 21:07:28 -0300
Subject: [PATCH] initialize source port and destination port if possible

---
 association.go | 21 +++++++++++++++++++--
 1 file changed, 19 insertions(+), 2 deletions(-)

diff --git a/association.go b/association.go
index cf493ef7..87fdd090 100644
--- a/association.go
+++ b/association.go
@@ -95,6 +95,16 @@ const (
 	acceptChSize = 16
 )
 
+func getPort(addr net.Addr) uint16 {
+	switch addr := addr.(type) {
+	case *net.UDPAddr:
+		return uint16(addr.Port)
+	case *net.TCPAddr:
+		return uint16(addr.Port)
+	}
+	return 0
+}
+
 func getAssociationStateString(a uint32) string {
 	switch a {
 	case closed:
@@ -295,6 +305,7 @@ func createAssociation(config Config) *Association {
 	}
 
 	tsn := globalMathRandomGenerator.Uint32()
+
 	a := &Association{
 		netConn:                 config.NetConn,
 		maxReceiveBufferSize:    maxReceiveBufferSize,
@@ -327,6 +338,8 @@ func createAssociation(config Config) *Association {
 		silentError:             ErrSilentlyDiscard,
 		stats:                   &associationStats{},
 		log:                     config.LoggerFactory.NewLogger("sctp"),
+		sourcePort:              getPort(config.NetConn.LocalAddr()),
+		destinationPort:         getPort(config.NetConn.RemoteAddr()),
 	}
 
 	a.name = fmt.Sprintf("%p", a)
@@ -391,8 +404,12 @@ func (a *Association) sendInit() error {
 
 	outbound := &packet{}
 	outbound.verificationTag = a.peerVerificationTag
-	a.sourcePort = 5000      // Spec??
-	a.destinationPort = 5000 // Spec??
+	if a.sourcePort == 0 {
+		a.sourcePort = 5000
+	}
+	if a.destinationPort == 0 {
+		a.destinationPort = 5000
+	}
 	outbound.sourcePort = a.sourcePort
 	outbound.destinationPort = a.destinationPort