[netstack] Decouple tcpip.ControlMessages from the IP control messges.

tcpip.ControlMessages can not contain Linux specific structures which makes it
painful to convert back and forth from Linux to tcpip back to Linux when passing
around control messages in hostinet and raw sockets.

Now we convert to the Linux version of the control message as soon as we are
out of tcpip.

PiperOrigin-RevId: 347027065

1 files changed, 73 insertions, 1 deletions

diff --git a/pkg/sentry/socket/socket.go b/pkg/sentry/socket/socket.go
index 9049e8a21..bcc426e33 100644
--- a/pkg/sentry/socket/socket.go
+++ b/pkg/sentry/socket/socket.go
@@ -44,7 +44,79 @@ import (
 // control messages.
 type ControlMessages struct {
 	Unix transport.ControlMessages
-	IP   tcpip.ControlMessages
+	IP   IPControlMessages
+}
+
+// packetInfoToLinux converts IPPacketInfo from tcpip format to Linux format.
+func packetInfoToLinux(packetInfo tcpip.IPPacketInfo) linux.ControlMessageIPPacketInfo {
+	var p linux.ControlMessageIPPacketInfo
+	p.NIC = int32(packetInfo.NIC)
+	copy(p.LocalAddr[:], []byte(packetInfo.LocalAddr))
+	copy(p.DestinationAddr[:], []byte(packetInfo.DestinationAddr))
+	return p
+}
+
+// NewIPControlMessages converts the tcpip ControlMessgaes (which does not
+// have Linux specific format) to Linux format.
+func NewIPControlMessages(family int, cmgs tcpip.ControlMessages) IPControlMessages {
+	var orgDstAddr linux.SockAddr
+	if cmgs.HasOriginalDstAddress {
+		orgDstAddr, _ = ConvertAddress(family, cmgs.OriginalDstAddress)
+	}
+	return IPControlMessages{
+		HasTimestamp:       cmgs.HasTimestamp,
+		Timestamp:          cmgs.Timestamp,
+		HasInq:             cmgs.HasInq,
+		Inq:                cmgs.Inq,
+		HasTOS:             cmgs.HasTOS,
+		TOS:                cmgs.TOS,
+		HasTClass:          cmgs.HasTClass,
+		TClass:             cmgs.TClass,
+		HasIPPacketInfo:    cmgs.HasIPPacketInfo,
+		PacketInfo:         packetInfoToLinux(cmgs.PacketInfo),
+		OriginalDstAddress: orgDstAddr,
+	}
+}
+
+// IPControlMessages contains socket control messages for IP sockets.
+// This can contain Linux specific structures unlike tcpip.ControlMessages.
+//
+// +stateify savable
+type IPControlMessages struct {
+	// HasTimestamp indicates whether Timestamp is valid/set.
+	HasTimestamp bool
+
+	// Timestamp is the time (in ns) that the last packet used to create
+	// the read data was received.
+	Timestamp int64
+
+	// HasInq indicates whether Inq is valid/set.
+	HasInq bool
+
+	// Inq is the number of bytes ready to be received.
+	Inq int32
+
+	// HasTOS indicates whether Tos is valid/set.
+	HasTOS bool
+
+	// TOS is the IPv4 type of service of the associated packet.
+	TOS uint8
+
+	// HasTClass indicates whether TClass is valid/set.
+	HasTClass bool
+
+	// TClass is the IPv6 traffic class of the associated packet.
+	TClass uint32
+
+	// HasIPPacketInfo indicates whether PacketInfo is set.
+	HasIPPacketInfo bool
+
+	// PacketInfo holds interface and address data on an incoming packet.
+	PacketInfo linux.ControlMessageIPPacketInfo
+
+	// OriginalDestinationAddress holds the original destination address
+	// and port of the incoming packet.
+	OriginalDstAddress linux.SockAddr
 }
 
 // Release releases Unix domain socket credentials and rights.