Add support for TCP_CONGESTION socket option.

This CL also cleans up the error returned for setting congestion
control which was incorrectly returning EINVAL instead of ENOENT.

PiperOrigin-RevId: 252889093

1 files changed, 29 insertions, 23 deletions

diff --git a/pkg/tcpip/transport/tcp/testing/context/context.go b/pkg/tcpip/transport/tcp/testing/context/context.go
index 69a43b6f4..a4d89e24d 100644
--- a/pkg/tcpip/transport/tcp/testing/context/context.go
+++ b/pkg/tcpip/transport/tcp/testing/context/context.go
@@ -520,35 +520,21 @@ func (c *Context) CreateConnected(iss seqnum.Value, rcvWnd seqnum.Size, epRcvBuf
 	c.CreateConnectedWithRawOptions(iss, rcvWnd, epRcvBuf, nil)
 }
 
-// CreateConnectedWithRawOptions creates a connected TCP endpoint and sends
-// the specified option bytes as the Option field in the initial SYN packet.
+// Connect performs the 3-way handshake for c.EP with the provided Initial
+// Sequence Number (iss) and receive window(rcvWnd) and any options if
+// specified.
 //
 // It also sets the receive buffer for the endpoint to the specified
 // value in epRcvBuf.
-func (c *Context) CreateConnectedWithRawOptions(iss seqnum.Value, rcvWnd seqnum.Size, epRcvBuf *tcpip.ReceiveBufferSizeOption, options []byte) {
-	// Create TCP endpoint.
-	var err *tcpip.Error
-	c.EP, err = c.s.NewEndpoint(tcp.ProtocolNumber, ipv4.ProtocolNumber, &c.WQ)
-	if err != nil {
-		c.t.Fatalf("NewEndpoint failed: %v", err)
-	}
-	if got, want := tcp.EndpointState(c.EP.State()), tcp.StateInitial; got != want {
-		c.t.Errorf("Unexpected endpoint state: want %v, got %v", want, got)
-	}
-
-	if epRcvBuf != nil {
-		if err := c.EP.SetSockOpt(*epRcvBuf); err != nil {
-			c.t.Fatalf("SetSockOpt failed failed: %v", err)
-		}
-	}
-
+//
+// PreCondition: c.EP must already be created.
+func (c *Context) Connect(iss seqnum.Value, rcvWnd seqnum.Size, options []byte) {
 	// Start connection attempt.
 	waitEntry, notifyCh := waiter.NewChannelEntry(nil)
 	c.WQ.EventRegister(&waitEntry, waiter.EventOut)
 	defer c.WQ.EventUnregister(&waitEntry)
 
-	err = c.EP.Connect(tcpip.FullAddress{Addr: TestAddr, Port: TestPort})
-	if err != tcpip.ErrConnectStarted {
+	if err := c.EP.Connect(tcpip.FullAddress{Addr: TestAddr, Port: TestPort}); err != tcpip.ErrConnectStarted {
 		c.t.Fatalf("Unexpected return value from Connect: %v", err)
 	}
 
@@ -590,8 +576,7 @@ func (c *Context) CreateConnectedWithRawOptions(iss seqnum.Value, rcvWnd seqnum.
 	// Wait for connection to be established.
 	select {
 	case <-notifyCh:
-		err = c.EP.GetSockOpt(tcpip.ErrorOption{})
-		if err != nil {
+		if err := c.EP.GetSockOpt(tcpip.ErrorOption{}); err != nil {
 			c.t.Fatalf("Unexpected error when connecting: %v", err)
 		}
 	case <-time.After(1 * time.Second):
@@ -604,6 +589,27 @@ func (c *Context) CreateConnectedWithRawOptions(iss seqnum.Value, rcvWnd seqnum.
 	c.Port = tcpHdr.SourcePort()
 }
 
+// CreateConnectedWithRawOptions creates a connected TCP endpoint and sends
+// the specified option bytes as the Option field in the initial SYN packet.
+//
+// It also sets the receive buffer for the endpoint to the specified
+// value in epRcvBuf.
+func (c *Context) CreateConnectedWithRawOptions(iss seqnum.Value, rcvWnd seqnum.Size, epRcvBuf *tcpip.ReceiveBufferSizeOption, options []byte) {
+	// Create TCP endpoint.
+	var err *tcpip.Error
+	c.EP, err = c.s.NewEndpoint(tcp.ProtocolNumber, ipv4.ProtocolNumber, &c.WQ)
+	if err != nil {
+		c.t.Fatalf("NewEndpoint failed: %v", err)
+	}
+
+	if epRcvBuf != nil {
+		if err := c.EP.SetSockOpt(*epRcvBuf); err != nil {
+			c.t.Fatalf("SetSockOpt failed failed: %v", err)
+		}
+	}
+	c.Connect(iss, rcvWnd, options)
+}
+
 // RawEndpoint is just a small wrapper around a TCP endpoint's state to make
 // sending data and ACK packets easy while being able to manipulate the sequence
 // numbers and timestamp values as needed.