1 files changed, 53 insertions, 23 deletions
diff --git a/pkg/tcpip/tcpip.go b/pkg/tcpip/tcpip.go
index 2bd472811..ef0f51f1a 100644
--- a/pkg/tcpip/tcpip.go
+++ b/pkg/tcpip/tcpip.go
@@ -49,8 +49,9 @@ const ipv4AddressSize = 4
 // Error represents an error in the netstack error space. Using a special type
 // ensures that errors outside of this space are not accidentally introduced.
 //
-// Note: to support save / restore, it is important that all tcpip errors have
-// distinct error messages.
+// All errors must have unique msg strings.
+//
+// +stateify savable
 type Error struct {
 	msg string
 
@@ -257,6 +258,44 @@ func (a Address) Unspecified() bool {
 	return true
 }
 
+// MatchingPrefix returns the matching prefix length in bits.
+//
+// Panics if b and a have different lengths.
+func (a Address) MatchingPrefix(b Address) uint8 {
+	const bitsInAByte = 8
+
+	if len(a) != len(b) {
+		panic(fmt.Sprintf("addresses %s and %s do not have the same length", a, b))
+	}
+
+	var prefix uint8
+	for i := range a {
+		aByte := a[i]
+		bByte := b[i]
+
+		if aByte == bByte {
+			prefix += bitsInAByte
+			continue
+		}
+
+		// Count the remaining matching bits in the byte from MSbit to LSBbit.
+		mask := uint8(1) << (bitsInAByte - 1)
+		for {
+			if aByte&mask == bByte&mask {
+				prefix++
+				mask >>= 1
+				continue
+			}
+
+			break
+		}
+
+		break
+	}
+
+	return prefix
+}
+
 // AddressMask is a bitmask for an address.
 type AddressMask string
 
@@ -491,6 +530,17 @@ type ControlMessages struct {
 
 	// PacketInfo holds interface and address data on an incoming packet.
 	PacketInfo IPPacketInfo
+
+	// HasOriginalDestinationAddress indicates whether OriginalDstAddress is
+	// set.
+	HasOriginalDstAddress bool
+
+	// OriginalDestinationAddress holds the original destination address
+	// and port of the incoming packet.
+	OriginalDstAddress FullAddress
+
+	// SockErr is the dequeued socket error on recvmsg(MSG_ERRQUEUE).
+	SockErr *SockError
 }
 
 // PacketOwner is used to get UID and GID of the packet.
@@ -545,7 +595,7 @@ type Endpoint interface {
 	// Peek reads data without consuming it from the endpoint.
 	//
 	// This method does not block if there is no data pending.
-	Peek([][]byte) (int64, ControlMessages, *Error)
+	Peek([][]byte) (int64, *Error)
 
 	// Connect connects the endpoint to its peer. Specifying a NIC is
 	// optional.
@@ -905,14 +955,6 @@ type SettableSocketOption interface {
 	isSettableSocketOption()
 }
 
-// BindToDeviceOption is used by SetSockOpt/GetSockOpt to specify that sockets
-// should bind only on a specific NIC.
-type BindToDeviceOption NICID
-
-func (*BindToDeviceOption) isGettableSocketOption() {}
-
-func (*BindToDeviceOption) isSettableSocketOption() {}
-
 // TCPInfoOption is used by GetSockOpt to expose TCP statistics.
 //
 // TODO(b/64800844): Add and populate stat fields.
@@ -1087,14 +1129,6 @@ type RemoveMembershipOption MembershipOption
 
 func (*RemoveMembershipOption) isSettableSocketOption() {}
 
-// OutOfBandInlineOption is used by SetSockOpt/GetSockOpt to specify whether
-// TCP out-of-band data is delivered along with the normal in-band data.
-type OutOfBandInlineOption int
-
-func (*OutOfBandInlineOption) isGettableSocketOption() {}
-
-func (*OutOfBandInlineOption) isSettableSocketOption() {}
-
 // SocketDetachFilterOption is used by SetSockOpt to detach a previously attached
 // classic BPF filter on a given endpoint.
 type SocketDetachFilterOption int
@@ -1144,10 +1178,6 @@ type LingerOption struct {
 	Timeout time.Duration
 }
 
-func (*LingerOption) isGettableSocketOption() {}
-
-func (*LingerOption) isSettableSocketOption() {}
-
 // IPPacketInfo is the message structure for IP_PKTINFO.
 //
 // +stateify savable