1 files changed, 34 insertions, 64 deletions

diff --git a/pkg/tcpip/socketops.go b/pkg/tcpip/socketops.go
index 0ea85f9ed..34ac62444 100644
--- a/pkg/tcpip/socketops.go
+++ b/pkg/tcpip/socketops.go
@@ -15,17 +15,12 @@
 package tcpip
 
 import (
-	"math"
 	"sync/atomic"
 
 	"gvisor.dev/gvisor/pkg/atomicbitops"
 	"gvisor.dev/gvisor/pkg/sync"
 )
 
-// PacketOverheadFactor is used to multiply the value provided by the user on a
-// SetSockOpt for setting the send/receive buffer sizes sockets.
-const PacketOverheadFactor = 2
-
 // SocketOptionsHandler holds methods that help define endpoint specific
 // behavior for socket level socket options. These must be implemented by
 // endpoints to get notified when socket level options are set.
@@ -60,8 +55,13 @@ type SocketOptionsHandler interface {
 	// buffer size. It also returns the newly set value.
 	OnSetSendBufferSize(v int64) (newSz int64)
 
-	// OnSetReceiveBufferSize is invoked to set the SO_RCVBUFSIZE.
+	// OnSetReceiveBufferSize is invoked by SO_RCVBUF and SO_RCVBUFFORCE.
 	OnSetReceiveBufferSize(v, oldSz int64) (newSz int64)
+
+	// WakeupWriters is invoked when the send buffer size for an endpoint is
+	// changed. The handler notifies the writers if the send buffer size is
+	// increased with setsockopt(2) for TCP endpoints.
+	WakeupWriters()
 }
 
 // DefaultSocketOptionsHandler is an embeddable type that implements no-op
@@ -103,6 +103,9 @@ func (*DefaultSocketOptionsHandler) OnSetSendBufferSize(v int64) (newSz int64) {
 	return v
 }
 
+// WakeupWriters implements SocketOptionsHandler.WakeupWriters.
+func (*DefaultSocketOptionsHandler) WakeupWriters() {}
+
 // OnSetReceiveBufferSize implements SocketOptionsHandler.OnSetReceiveBufferSize.
 func (*DefaultSocketOptionsHandler) OnSetReceiveBufferSize(v, oldSz int64) (newSz int64) {
 	return v
@@ -617,39 +620,23 @@ func (so *SocketOptions) GetSendBufferSize() int64 {
 	return so.sendBufferSize.Load()
 }
 
+// SendBufferLimits returns the [min, max) range of allowable send buffer
+// sizes.
+func (so *SocketOptions) SendBufferLimits() (min, max int64) {
+	limits := so.getSendBufferLimits(so.stackHandler)
+	return int64(limits.Min), int64(limits.Max)
+}
+
 // SetSendBufferSize sets value for SO_SNDBUF option. notify indicates if the
 // stack handler should be invoked to set the send buffer size.
 func (so *SocketOptions) SetSendBufferSize(sendBufferSize int64, notify bool) {
-	v := sendBufferSize
-
-	if !notify {
-		so.sendBufferSize.Store(v)
-		return
-	}
-
-	// Make sure the send buffer size is within the min and max
-	// allowed.
-	ss := so.getSendBufferLimits(so.stackHandler)
-	min := int64(ss.Min)
-	max := int64(ss.Max)
-	// Validate the send buffer size with min and max values.
-	// Multiply it by factor of 2.
-	if v > max {
-		v = max
+	if notify {
+		sendBufferSize = so.handler.OnSetSendBufferSize(sendBufferSize)
 	}
-
-	if v < math.MaxInt32/PacketOverheadFactor {
-		v *= PacketOverheadFactor
-		if v < min {
-			v = min
-		}
-	} else {
-		v = math.MaxInt32
+	so.sendBufferSize.Store(sendBufferSize)
+	if notify {
+		so.handler.WakeupWriters()
 	}
-
-	// Notify endpoint about change in buffer size.
-	newSz := so.handler.OnSetSendBufferSize(v)
-	so.sendBufferSize.Store(newSz)
 }
 
 // GetReceiveBufferSize gets value for SO_RCVBUF option.
@@ -657,36 +644,19 @@ func (so *SocketOptions) GetReceiveBufferSize() int64 {
 	return so.receiveBufferSize.Load()
 }
 
-// SetReceiveBufferSize sets value for SO_RCVBUF option.
-func (so *SocketOptions) SetReceiveBufferSize(receiveBufferSize int64, notify bool) {
-	if !notify {
-		so.receiveBufferSize.Store(receiveBufferSize)
-		return
-	}
-
-	// Make sure the send buffer size is within the min and max
-	// allowed.
-	v := receiveBufferSize
-	ss := so.getReceiveBufferLimits(so.stackHandler)
-	min := int64(ss.Min)
-	max := int64(ss.Max)
-	// Validate the send buffer size with min and max values.
-	if v > max {
-		v = max
-	}
+// ReceiveBufferLimits returns the [min, max) range of allowable receive buffer
+// sizes.
+func (so *SocketOptions) ReceiveBufferLimits() (min, max int64) {
+	limits := so.getReceiveBufferLimits(so.stackHandler)
+	return int64(limits.Min), int64(limits.Max)
+}
 
-	// Multiply it by factor of 2.
-	if v < math.MaxInt32/PacketOverheadFactor {
-		v *= PacketOverheadFactor
-		if v < min {
-			v = min
-		}
-	} else {
-		v = math.MaxInt32
+// SetReceiveBufferSize sets the value of the SO_RCVBUF option, optionally
+// notifying the owning endpoint.
+func (so *SocketOptions) SetReceiveBufferSize(receiveBufferSize int64, notify bool) {
+	if notify {
+		oldSz := so.receiveBufferSize.Load()
+		receiveBufferSize = so.handler.OnSetReceiveBufferSize(receiveBufferSize, oldSz)
 	}
-
-	oldSz := so.receiveBufferSize.Load()
-	// Notify endpoint about change in buffer size.
-	newSz := so.handler.OnSetReceiveBufferSize(v, oldSz)
-	so.receiveBufferSize.Store(newSz)
+	so.receiveBufferSize.Store(receiveBufferSize)
 }