From 07585948362039b57f296b725ef821206a57ed86 Mon Sep 17 00:00:00 2001
From: Tim Liu <timliu@nctu.edu.tw>
Date: Fri, 26 Jul 2024 08:50:29 +0000
Subject: [PATCH] feat: add local sctp address config

---
 internal/ngap/server.go |  2 +-
 pkg/factory/config.go   | 22 ++++++++++++++++++++--
 2 files changed, 21 insertions(+), 3 deletions(-)

diff --git a/internal/ngap/server.go b/internal/ngap/server.go
index 2b5c0db..b94498e 100644
--- a/internal/ngap/server.go
+++ b/internal/ngap/server.go
@@ -58,7 +58,7 @@ func (s *Server) Run(wg *sync.WaitGroup) error {
 	// n3iwf context
 	cfg := s.Config()
 
-	localAddr := new(sctp.SCTPAddr)
+	localAddr := cfg.GetLocalSctpAddr()
 
 	for _, remoteAddr := range cfg.GetAmfSctpAddrs() {
 		errChan := make(chan error)
diff --git a/pkg/factory/config.go b/pkg/factory/config.go
index ffc2eab..2dbed9a 100644
--- a/pkg/factory/config.go
+++ b/pkg/factory/config.go
@@ -115,8 +115,9 @@ type Info struct {
 }
 
 type Configuration struct {
-	N3IWFInfo        *N3IWFNFInfo       `yaml:"N3IWFInformation" valid:"required"`
-	AMFSCTPAddresses []AMFSCTPAddresses `yaml:"AMFSCTPAddresses" valid:"required"`
+	N3IWFInfo        *N3IWFNFInfo       `yaml:"N3IWFInformation"        valid:"required"`
+	LocalSctpAddr    string             `yaml:"localSctpAddr,omitempty" valid:"optional,host"`
+	AMFSCTPAddresses []AMFSCTPAddresses `yaml:"AMFSCTPAddresses"        valid:"required"`
 
 	TCPPort              int         `yaml:"NASTCPPort"           valid:"required,port"`
 	IKEBindAddr          string      `yaml:"IKEBindAddress"       valid:"required,host"`
@@ -255,6 +256,23 @@ func (c *Config) GetRanNodeName() string {
 	return c.Configuration.N3IWFInfo.RanNodeName
 }
 
+func (c *Config) GetLocalSctpAddr() *sctp.SCTPAddr {
+	c.RLock()
+	defer c.RUnlock()
+
+	sctpAddr := new(sctp.SCTPAddr)
+	localAddr := c.Configuration.LocalSctpAddr
+	if localAddr != "" {
+		ipAddr, err := net.ResolveIPAddr("ip", localAddr)
+		if err == nil {
+			sctpAddr = &sctp.SCTPAddr{
+				IPAddrs: []net.IPAddr{*ipAddr},
+			}
+		}
+	}
+	return sctpAddr
+}
+
 func (c *Config) GetAmfSctpAddrs() []*sctp.SCTPAddr {
 	c.RLock()
 	defer c.RUnlock()