Unexpose immutable fields in stack.Route

This change sets the inner `routeInfo` struct to be a named private member
and replaces direct access with access through getters. Note that direct
access to the fields of `routeInfo` is still possible through the `RouteInfo`
struct.

Fixes #4902

PiperOrigin-RevId: 364822872

2 files changed, 11 insertions, 11 deletions

diff --git a/pkg/tcpip/network/ipv4/icmp.go b/pkg/tcpip/network/ipv4/icmp.go
index deb104837..1525f15db 100644
--- a/pkg/tcpip/network/ipv4/icmp.go
+++ b/pkg/tcpip/network/ipv4/icmp.go
@@ -305,8 +305,8 @@ func (e *endpoint) handleICMP(pkt *stack.PacketBuffer) {
 		// We need to produce the entire packet in the data segment in order to
 		// use WriteHeaderIncludedPacket(). WriteHeaderIncludedPacket sets the
 		// total length and the header checksum so we don't need to set those here.
-		replyIPHdr.SetSourceAddress(r.LocalAddress)
-		replyIPHdr.SetDestinationAddress(r.RemoteAddress)
+		replyIPHdr.SetSourceAddress(r.LocalAddress())
+		replyIPHdr.SetDestinationAddress(r.RemoteAddress())
 		replyIPHdr.SetTTL(r.DefaultTTL())
 
 		replyICMPHdr := header.ICMPv4(replyData)
diff --git a/pkg/tcpip/network/ipv4/ipv4.go b/pkg/tcpip/network/ipv4/ipv4.go
index a1660e9a3..1a5661ca4 100644
--- a/pkg/tcpip/network/ipv4/ipv4.go
+++ b/pkg/tcpip/network/ipv4/ipv4.go
@@ -339,7 +339,7 @@ func (e *endpoint) handleFragments(r *stack.Route, gso *stack.GSO, networkMTU ui
 
 // WritePacket writes a packet to the given destination address and protocol.
 func (e *endpoint) WritePacket(r *stack.Route, gso *stack.GSO, params stack.NetworkHeaderParams, pkt *stack.PacketBuffer) tcpip.Error {
-	if err := e.addIPHeader(r.LocalAddress, r.RemoteAddress, pkt, params, nil /* options */); err != nil {
+	if err := e.addIPHeader(r.LocalAddress(), r.RemoteAddress(), pkt, params, nil /* options */); err != nil {
 		return err
 	}
 
@@ -373,13 +373,13 @@ func (e *endpoint) WritePacket(r *stack.Route, gso *stack.GSO, params stack.Netw
 }
 
 func (e *endpoint) writePacket(r *stack.Route, gso *stack.GSO, pkt *stack.PacketBuffer, headerIncluded bool) tcpip.Error {
-	if r.Loop&stack.PacketLoop != 0 {
+	if r.Loop()&stack.PacketLoop != 0 {
 		// If the packet was generated by the stack (not a raw/packet endpoint
 		// where a packet may be written with the header included), then we can
 		// safely assume the checksum is valid.
 		e.handleLocalPacket(pkt, !headerIncluded /* canSkipRXChecksum */)
 	}
-	if r.Loop&stack.PacketOut == 0 {
+	if r.Loop()&stack.PacketOut == 0 {
 		return nil
 	}
 
@@ -414,17 +414,17 @@ func (e *endpoint) writePacket(r *stack.Route, gso *stack.GSO, pkt *stack.Packet
 
 // WritePackets implements stack.NetworkEndpoint.WritePackets.
 func (e *endpoint) WritePackets(r *stack.Route, gso *stack.GSO, pkts stack.PacketBufferList, params stack.NetworkHeaderParams) (int, tcpip.Error) {
-	if r.Loop&stack.PacketLoop != 0 {
+	if r.Loop()&stack.PacketLoop != 0 {
 		panic("multiple packets in local loop")
 	}
-	if r.Loop&stack.PacketOut == 0 {
+	if r.Loop()&stack.PacketOut == 0 {
 		return pkts.Len(), nil
 	}
 
 	stats := e.stats.ip
 
 	for pkt := pkts.Front(); pkt != nil; pkt = pkt.Next() {
-		if err := e.addIPHeader(r.LocalAddress, r.RemoteAddress, pkt, params, nil /* options */); err != nil {
+		if err := e.addIPHeader(r.LocalAddress(), r.RemoteAddress(), pkt, params, nil /* options */); err != nil {
 			return 0, err
 		}
 
@@ -514,12 +514,12 @@ func (e *endpoint) WriteHeaderIncludedPacket(r *stack.Route, pkt *stack.PacketBu
 
 	// Set the source address when zero.
 	if ip.SourceAddress() == header.IPv4Any {
-		ip.SetSourceAddress(r.LocalAddress)
+		ip.SetSourceAddress(r.LocalAddress())
 	}
 
 	// Set the destination. If the packet already included a destination, it will
 	// be part of the route anyways.
-	ip.SetDestinationAddress(r.RemoteAddress)
+	ip.SetDestinationAddress(r.RemoteAddress())
 
 	// Set the packet ID when zero.
 	if ip.ID() == 0 {
@@ -527,7 +527,7 @@ func (e *endpoint) WriteHeaderIncludedPacket(r *stack.Route, pkt *stack.PacketBu
 		// non-atomic datagrams, so assign an ID to all such datagrams
 		// according to the definition given in RFC 6864 section 4.
 		if ip.Flags()&header.IPv4FlagDontFragment == 0 || ip.Flags()&header.IPv4FlagMoreFragments != 0 || ip.FragmentOffset() > 0 {
-			ip.SetID(uint16(atomic.AddUint32(&e.protocol.ids[hashRoute(r.LocalAddress, r.RemoteAddress, 0 /* protocol */, e.protocol.hashIV)%buckets], 1)))
+			ip.SetID(uint16(atomic.AddUint32(&e.protocol.ids[hashRoute(r.LocalAddress(), r.RemoteAddress(), 0 /* protocol */, e.protocol.hashIV)%buckets], 1)))
 		}
 	}