From 3213c504a9d61d4382fd965c6d0a3ddc56555613 Mon Sep 17 00:00:00 2001
From: Yutaka Takeda <yt0916@gmail.com>
Date: Sat, 23 Apr 2022 13:27:32 -0700
Subject: [PATCH 1/2] Max recv buf size via SettingEngine

Relates to pion/sctp#218
---
 sctptransport.go | 5 +++--
 settingengine.go | 9 +++++++++
 2 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/sctptransport.go b/sctptransport.go
index 27e02ea65de..a379a96b1e1 100644
--- a/sctptransport.go
+++ b/sctptransport.go
@@ -103,8 +103,9 @@ func (r *SCTPTransport) Start(remoteCaps SCTPCapabilities) error {
 	}
 
 	sctpAssociation, err := sctp.Client(sctp.Config{
-		NetConn:       dtlsTransport.conn,
-		LoggerFactory: r.api.settingEngine.LoggerFactory,
+		NetConn:              dtlsTransport.conn,
+		MaxReceiveBufferSize: r.api.settingEngine.sctp.maxReceiveBufferSize,
+		LoggerFactory:        r.api.settingEngine.LoggerFactory,
 	})
 	if err != nil {
 		return err
diff --git a/settingengine.go b/settingengine.go
index a2f5ef41882..7cd0bb30881 100644
--- a/settingengine.go
+++ b/settingengine.go
@@ -54,6 +54,9 @@ type SettingEngine struct {
 	dtls struct {
 		retransmissionInterval time.Duration
 	}
+	sctp struct {
+		maxReceiveBufferSize uint32
+	}
 	sdpMediaLevelFingerprints                 bool
 	answeringDTLSRole                         DTLSRole
 	disableCertificateFingerprintVerification bool
@@ -304,3 +307,9 @@ func (e *SettingEngine) SetReceiveMTU(receiveMTU uint) {
 func (e *SettingEngine) SetDTLSRetransmissionInterval(interval time.Duration) {
 	e.dtls.retransmissionInterval = interval
 }
+
+// SetSCTPMaxReceiveBufferSize sets the maximum receive buffer size.
+// Leave this 0 for the default maxReceiveBufferSize.
+func (e *SettingEngine) SetSCTPMaxReceiveBufferSize(maxReceiveBufferSize uint32) {
+	e.sctp.maxReceiveBufferSize = maxReceiveBufferSize
+}

From 1ef4789b7ec4b2af6b2fd7f19fd5864de0c879ce Mon Sep 17 00:00:00 2001
From: Yutaka Takeda <yt0916@gmail.com>
Date: Sat, 23 Apr 2022 15:04:41 -0700
Subject: [PATCH 2/2] Added a unit test

Relates to pion/sctp#218
---
 settingengine_test.go | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/settingengine_test.go b/settingengine_test.go
index 80817ca34bf..dd661d5e255 100644
--- a/settingengine_test.go
+++ b/settingengine_test.go
@@ -233,3 +233,12 @@ func TestSetDTLSRetransmissionInterval(t *testing.T) {
 		t.Errorf("Failed to set DTLS retransmission interval")
 	}
 }
+
+func TestSetSCTPMaxReceiverBufferSize(t *testing.T) {
+	s := SettingEngine{}
+	assert.Equal(t, uint32(0), s.sctp.maxReceiveBufferSize)
+
+	expSize := uint32(4 * 1024 * 1024)
+	s.SetSCTPMaxReceiveBufferSize(expSize)
+	assert.Equal(t, expSize, s.sctp.maxReceiveBufferSize)
+}