3 files changed, 50 insertions, 67 deletions
diff --git a/pkg/sentry/socket/netstack/netstack.go b/pkg/sentry/socket/netstack/netstack.go
index 5d5c4ebbd..ea736e446 100644
--- a/pkg/sentry/socket/netstack/netstack.go
+++ b/pkg/sentry/socket/netstack/netstack.go
@@ -1682,6 +1682,26 @@ func SetSockOpt(t *kernel.Task, s socket.SocketOps, ep commonEndpoint, level int
 	return nil
 }
 
+func clampBufSize(newSz, min, max int64) int64 {
+	// packetOverheadFactor is used to multiply the value provided by the user on
+	// a setsockopt(2) for setting the send/receive buffer sizes sockets.
+	const packetOverheadFactor = 2
+
+	if newSz > max {
+		newSz = max
+	}
+
+	if newSz < math.MaxInt32/packetOverheadFactor {
+		newSz *= packetOverheadFactor
+		if newSz < min {
+			newSz = min
+		}
+	} else {
+		newSz = math.MaxInt32
+	}
+	return newSz
+}
+
 // setSockOptSocket implements SetSockOpt when level is SOL_SOCKET.
 func setSockOptSocket(t *kernel.Task, s socket.SocketOps, ep commonEndpoint, name int, optVal []byte) *syserr.Error {
 	switch name {
@@ -1691,7 +1711,9 @@ func setSockOptSocket(t *kernel.Task, s socket.SocketOps, ep commonEndpoint, nam
 		}
 
 		v := hostarch.ByteOrder.Uint32(optVal)
-		ep.SocketOptions().SetSendBufferSize(int64(v), true /* notify */)
+		min, max := ep.SocketOptions().SendBufferLimits()
+		clamped := clampBufSize(int64(v), min, max)
+		ep.SocketOptions().SetSendBufferSize(clamped, true /* notify */)
 		return nil
 
 	case linux.SO_RCVBUF:
@@ -1700,7 +1722,9 @@ func setSockOptSocket(t *kernel.Task, s socket.SocketOps, ep commonEndpoint, nam
 		}
 
 		v := hostarch.ByteOrder.Uint32(optVal)
-		ep.SocketOptions().SetReceiveBufferSize(int64(v), true /* notify */)
+		min, max := ep.SocketOptions().ReceiveBufferLimits()
+		clamped := clampBufSize(int64(v), min, max)
+		ep.SocketOptions().SetReceiveBufferSize(clamped, true /* notify */)
 		return nil
 
 	case linux.SO_REUSEADDR:
diff --git a/pkg/tcpip/socketops.go b/pkg/tcpip/socketops.go
index 0ea85f9ed..cc735c9ce 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.
@@ -617,39 +612,20 @@ 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 v < math.MaxInt32/PacketOverheadFactor {
-		v *= PacketOverheadFactor
-		if v < min {
-			v = min
-		}
-	} else {
-		v = math.MaxInt32
+	if notify {
+		sendBufferSize = so.handler.OnSetSendBufferSize(sendBufferSize)
 	}
-
-	// Notify endpoint about change in buffer size.
-	newSz := so.handler.OnSetSendBufferSize(v)
-	so.sendBufferSize.Store(newSz)
+	so.sendBufferSize.Store(sendBufferSize)
 }
 
 // GetReceiveBufferSize gets value for SO_RCVBUF option.
@@ -657,36 +633,19 @@ 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)
 }
diff --git a/pkg/tcpip/transport/raw/endpoint.go b/pkg/tcpip/transport/raw/endpoint.go
index b6687911a..ab5da987a 100644
--- a/pkg/tcpip/transport/raw/endpoint.go
+++ b/pkg/tcpip/transport/raw/endpoint.go
@@ -132,7 +132,7 @@ func newEndpoint(s *stack.Stack, netProto tcpip.NetworkProtocolNumber, transProt
 	// headers included. Because they're write-only, We don't need to
 	// register with the stack.
 	if !associated {
-		e.ops.SetReceiveBufferSize(0, false)
+		e.ops.SetReceiveBufferSize(0, false /* notify */)
 		e.waiterQueue = nil
 		return e, nil
 	}