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

2 files changed, 4 insertions, 55 deletions

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()