Move SO_TIMESTAMP from different transport endpoints to epsocket.

SO_TIMESTAMP is reimplemented in ping and UDP sockets (and needs to be added for
TCP), but can just be implemented in epsocket for simplicity. This will also
make SIOCGSTAMP easier to implement.

PiperOrigin-RevId: 234179300
Change-Id: Ib5ea0b1261dc218c1a8b15a65775de0050fe3230

3 files changed, 4 insertions, 65 deletions

diff --git a/pkg/tcpip/tcpip.go b/pkg/tcpip/tcpip.go
index fef5ba0e4..3cd431d4c 100644
--- a/pkg/tcpip/tcpip.go
+++ b/pkg/tcpip/tcpip.go
@@ -298,9 +298,6 @@ type Endpoint interface {
 	//
 	// This method does not block if there is no data pending. It will also
 	// either return an error or data, never both.
-	//
-	// A timestamp (in ns) is optionally returned. A zero value indicates
-	// that no timestamp was available.
 	Read(*FullAddress) (buffer.View, ControlMessages, *Error)
 
 	// Write writes data to the endpoint's peer. This method does not block if
@@ -326,9 +323,6 @@ type Endpoint interface {
 	// Peek reads data without consuming it from the endpoint.
 	//
 	// This method does not block if there is no data pending.
-	//
-	// A timestamp (in ns) is optionally returned. A zero value indicates
-	// that no timestamp was available.
 	Peek([][]byte) (uintptr, ControlMessages, *Error)
 
 	// Connect connects the endpoint to its peer. Specifying a NIC is
@@ -449,10 +443,6 @@ type QuickAckOption int
 // Only supported on Unix sockets.
 type PasscredOption int
 
-// TimestampOption is used by SetSockOpt/GetSockOpt to specify whether
-// SO_TIMESTAMP socket control messages are enabled.
-type TimestampOption int
-
 // TCPInfoOption is used by GetSockOpt to expose TCP statistics.
 //
 // TODO: Add and populate stat fields.
diff --git a/pkg/tcpip/transport/ping/endpoint.go b/pkg/tcpip/transport/ping/endpoint.go
index 29f6c543d..c8263a512 100644
--- a/pkg/tcpip/transport/ping/endpoint.go
+++ b/pkg/tcpip/transport/ping/endpoint.go
@@ -32,7 +32,6 @@ type pingPacket struct {
 	senderAddress tcpip.FullAddress
 	data          buffer.VectorisedView `state:".(buffer.VectorisedView)"`
 	timestamp     int64
-	hasTimestamp  bool
 	// views is used as buffer for data when its length is large
 	// enough to store a VectorisedView.
 	views [8]buffer.View `state:"nosave"`
@@ -67,7 +66,6 @@ type endpoint struct {
 	rcvBufSizeMax int `state:".(int)"`
 	rcvBufSize    int
 	rcvClosed     bool
-	rcvTimestamp  bool
 
 	// The following fields are protected by the mu mutex.
 	mu         sync.RWMutex `state:"nosave"`
@@ -140,7 +138,6 @@ func (e *endpoint) Read(addr *tcpip.FullAddress) (buffer.View, tcpip.ControlMess
 	p := e.rcvList.Front()
 	e.rcvList.Remove(p)
 	e.rcvBufSize -= p.data.Size()
-	ts := e.rcvTimestamp
 
 	e.rcvMu.Unlock()
 
@@ -148,12 +145,7 @@ func (e *endpoint) Read(addr *tcpip.FullAddress) (buffer.View, tcpip.ControlMess
 		*addr = p.senderAddress
 	}
 
-	if ts && !p.hasTimestamp {
-		// Linux uses the current time.
-		p.timestamp = e.stack.NowNanoseconds()
-	}
-
-	return p.data.ToView(), tcpip.ControlMessages{HasTimestamp: ts, Timestamp: p.timestamp}, nil
+	return p.data.ToView(), tcpip.ControlMessages{HasTimestamp: true, Timestamp: p.timestamp}, nil
 }
 
 // prepareForWrite prepares the endpoint for sending data. In particular, it
@@ -313,12 +305,6 @@ func (e *endpoint) Peek([][]byte) (uintptr, tcpip.ControlMessages, *tcpip.Error)
 
 // SetSockOpt sets a socket option. Currently not supported.
 func (e *endpoint) SetSockOpt(opt interface{}) *tcpip.Error {
-	switch v := opt.(type) {
-	case tcpip.TimestampOption:
-		e.rcvMu.Lock()
-		e.rcvTimestamp = v != 0
-		e.rcvMu.Unlock()
-	}
 	return nil
 }
 
@@ -351,15 +337,6 @@ func (e *endpoint) GetSockOpt(opt interface{}) *tcpip.Error {
 		e.rcvMu.Unlock()
 		return nil
 
-	case *tcpip.TimestampOption:
-		e.rcvMu.Lock()
-		*o = 0
-		if e.rcvTimestamp {
-			*o = 1
-		}
-		e.rcvMu.Unlock()
-		return nil
-
 	case *tcpip.KeepaliveEnabledOption:
 		*o = 0
 		return nil
@@ -702,10 +679,7 @@ func (e *endpoint) HandlePacket(r *stack.Route, id stack.TransportEndpointID, vv
 	e.rcvList.PushBack(pkt)
 	e.rcvBufSize += vv.Size()
 
-	if e.rcvTimestamp {
-		pkt.timestamp = e.stack.NowNanoseconds()
-		pkt.hasTimestamp = true
-	}
+	pkt.timestamp = e.stack.NowNanoseconds()
 
 	e.rcvMu.Unlock()
 
diff --git a/pkg/tcpip/transport/udp/endpoint.go b/pkg/tcpip/transport/udp/endpoint.go
index d46bf0ade..fa8f02e46 100644
--- a/pkg/tcpip/transport/udp/endpoint.go
+++ b/pkg/tcpip/transport/udp/endpoint.go
@@ -32,7 +32,6 @@ type udpPacket struct {
 	senderAddress tcpip.FullAddress
 	data          buffer.VectorisedView `state:".(buffer.VectorisedView)"`
 	timestamp     int64
-	hasTimestamp  bool
 	// views is used as buffer for data when its length is large
 	// enough to store a VectorisedView.
 	views [8]buffer.View `state:"nosave"`
@@ -68,7 +67,6 @@ type endpoint struct {
 	rcvBufSizeMax int `state:".(int)"`
 	rcvBufSize    int
 	rcvClosed     bool
-	rcvTimestamp  bool
 
 	// The following fields are protected by the mu mutex.
 	mu           sync.RWMutex `state:"nosave"`
@@ -203,7 +201,6 @@ func (e *endpoint) Read(addr *tcpip.FullAddress) (buffer.View, tcpip.ControlMess
 	p := e.rcvList.Front()
 	e.rcvList.Remove(p)
 	e.rcvBufSize -= p.data.Size()
-	ts := e.rcvTimestamp
 
 	e.rcvMu.Unlock()
 
@@ -211,12 +208,7 @@ func (e *endpoint) Read(addr *tcpip.FullAddress) (buffer.View, tcpip.ControlMess
 		*addr = p.senderAddress
 	}
 
-	if ts && !p.hasTimestamp {
-		// Linux uses the current time.
-		p.timestamp = e.stack.NowNanoseconds()
-	}
-
-	return p.data.ToView(), tcpip.ControlMessages{HasTimestamp: ts, Timestamp: p.timestamp}, nil
+	return p.data.ToView(), tcpip.ControlMessages{HasTimestamp: true, Timestamp: p.timestamp}, nil
 }
 
 // prepareForWrite prepares the endpoint for sending data. In particular, it
@@ -397,11 +389,6 @@ func (e *endpoint) SetSockOpt(opt interface{}) *tcpip.Error {
 
 		e.v6only = v != 0
 
-	case tcpip.TimestampOption:
-		e.rcvMu.Lock()
-		e.rcvTimestamp = v != 0
-		e.rcvMu.Unlock()
-
 	case tcpip.MulticastTTLOption:
 		e.mu.Lock()
 		e.multicastTTL = uint8(v)
@@ -508,15 +495,6 @@ func (e *endpoint) GetSockOpt(opt interface{}) *tcpip.Error {
 		e.rcvMu.Unlock()
 		return nil
 
-	case *tcpip.TimestampOption:
-		e.rcvMu.Lock()
-		*o = 0
-		if e.rcvTimestamp {
-			*o = 1
-		}
-		e.rcvMu.Unlock()
-		return nil
-
 	case *tcpip.MulticastTTLOption:
 		e.mu.Lock()
 		*o = tcpip.MulticastTTLOption(e.multicastTTL)
@@ -909,10 +887,7 @@ func (e *endpoint) HandlePacket(r *stack.Route, id stack.TransportEndpointID, vv
 	e.rcvList.PushBack(pkt)
 	e.rcvBufSize += vv.Size()
 
-	if e.rcvTimestamp {
-		pkt.timestamp = e.stack.NowNanoseconds()
-		pkt.hasTimestamp = true
-	}
+	pkt.timestamp = e.stack.NowNanoseconds()
 
 	e.rcvMu.Unlock()