Stub out SO_DETACH_FILTER.

Updates #2746

PiperOrigin-RevId: 320757963

7 files changed, 33 insertions, 3 deletions

diff --git a/pkg/sentry/socket/netstack/netstack.go b/pkg/sentry/socket/netstack/netstack.go
index 5a3cedd7c..78a842973 100644
--- a/pkg/sentry/socket/netstack/netstack.go
+++ b/pkg/sentry/socket/netstack/netstack.go
@@ -1754,6 +1754,11 @@ func setSockOptSocket(t *kernel.Task, s socket.SocketOps, ep commonEndpoint, nam
 
 		return nil
 
+	case linux.SO_DETACH_FILTER:
+		// optval is ignored.
+		var v tcpip.SocketDetachFilterOption
+		return syserr.TranslateNetstackError(ep.SetSockOpt(v))
+
 	default:
 		socket.SetSockOptEmitUnimplementedEvent(t, name)
 	}
diff --git a/pkg/tcpip/tcpip.go b/pkg/tcpip/tcpip.go
index cf7291d09..71bcee785 100644
--- a/pkg/tcpip/tcpip.go
+++ b/pkg/tcpip/tcpip.go
@@ -855,7 +855,10 @@ type OutOfBandInlineOption int
 // a default TTL.
 type DefaultTTLOption uint8
 
-//
+// SocketDetachFilterOption is used by SetSockOpt to detach a previously attached
+// classic BPF filter on a given endpoint.
+type SocketDetachFilterOption int
+
 // IPPacketInfo is the message structure for IP_PKTINFO.
 //
 // +stateify savable
diff --git a/pkg/tcpip/transport/icmp/endpoint.go b/pkg/tcpip/transport/icmp/endpoint.go
index 62d1acad4..678f4e016 100644
--- a/pkg/tcpip/transport/icmp/endpoint.go
+++ b/pkg/tcpip/transport/icmp/endpoint.go
@@ -344,6 +344,10 @@ func (e *endpoint) Peek([][]byte) (int64, tcpip.ControlMessages, *tcpip.Error) {
 
 // SetSockOpt sets a socket option.
 func (e *endpoint) SetSockOpt(opt interface{}) *tcpip.Error {
+	switch opt.(type) {
+	case tcpip.SocketDetachFilterOption:
+		return nil
+	}
 	return nil
 }
 
diff --git a/pkg/tcpip/transport/packet/endpoint.go b/pkg/tcpip/transport/packet/endpoint.go
index a8f8454dd..57b7f5c19 100644
--- a/pkg/tcpip/transport/packet/endpoint.go
+++ b/pkg/tcpip/transport/packet/endpoint.go
@@ -278,7 +278,13 @@ func (ep *endpoint) Readiness(mask waiter.EventMask) waiter.EventMask {
 // used with SetSockOpt, and this function always returns
 // tcpip.ErrNotSupported.
 func (ep *endpoint) SetSockOpt(opt interface{}) *tcpip.Error {
-	return tcpip.ErrUnknownProtocolOption
+	switch opt.(type) {
+	case tcpip.SocketDetachFilterOption:
+		return nil
+
+	default:
+		return tcpip.ErrUnknownProtocolOption
+	}
 }
 
 // SetSockOptBool implements tcpip.Endpoint.SetSockOptBool.
diff --git a/pkg/tcpip/transport/raw/endpoint.go b/pkg/tcpip/transport/raw/endpoint.go
index 5b6e7d102..c2e9fd29f 100644
--- a/pkg/tcpip/transport/raw/endpoint.go
+++ b/pkg/tcpip/transport/raw/endpoint.go
@@ -506,7 +506,13 @@ func (e *endpoint) Readiness(mask waiter.EventMask) waiter.EventMask {
 
 // SetSockOpt implements tcpip.Endpoint.SetSockOpt.
 func (e *endpoint) SetSockOpt(opt interface{}) *tcpip.Error {
-	return tcpip.ErrUnknownProtocolOption
+	switch opt.(type) {
+	case tcpip.SocketDetachFilterOption:
+		return nil
+
+	default:
+		return tcpip.ErrUnknownProtocolOption
+	}
 }
 
 // SetSockOptBool implements tcpip.Endpoint.SetSockOptBool.
diff --git a/pkg/tcpip/transport/tcp/endpoint.go b/pkg/tcpip/transport/tcp/endpoint.go
index caac6ef57..83dc10ed0 100644
--- a/pkg/tcpip/transport/tcp/endpoint.go
+++ b/pkg/tcpip/transport/tcp/endpoint.go
@@ -1792,6 +1792,9 @@ func (e *endpoint) SetSockOpt(opt interface{}) *tcpip.Error {
 		e.deferAccept = time.Duration(v)
 		e.UnlockUser()
 
+	case tcpip.SocketDetachFilterOption:
+		return nil
+
 	default:
 		return nil
 	}
diff --git a/pkg/tcpip/transport/udp/endpoint.go b/pkg/tcpip/transport/udp/endpoint.go
index 4e9e114a9..a14643ae8 100644
--- a/pkg/tcpip/transport/udp/endpoint.go
+++ b/pkg/tcpip/transport/udp/endpoint.go
@@ -816,6 +816,9 @@ func (e *endpoint) SetSockOpt(opt interface{}) *tcpip.Error {
 		e.mu.Lock()
 		e.bindToDevice = id
 		e.mu.Unlock()
+
+	case tcpip.SocketDetachFilterOption:
+		return nil
 	}
 	return nil
 }