Use tcpip.Subnet in tcpip.Route

This is the first step in replacing some of the redundant types with the
standard library equivalents.

PiperOrigin-RevId: 264706552

2 files changed, 48 insertions, 25 deletions

diff --git a/runsc/boot/network.go b/runsc/boot/network.go
index d3d98243d..ea0d9f790 100644
--- a/runsc/boot/network.go
+++ b/runsc/boot/network.go
@@ -38,8 +38,7 @@ type Network struct {
 
 // Route represents a route in the network stack.
 type Route struct {
-	Destination net.IP
-	Mask        net.IPMask
+	Destination net.IPNet
 	Gateway     net.IP
 }
 
@@ -85,16 +84,19 @@ type CreateLinksAndRoutesArgs struct {
 
 // Empty returns true if route hasn't been set.
 func (r *Route) Empty() bool {
-	return r.Destination == nil && r.Mask == nil && r.Gateway == nil
+	return r.Destination.IP == nil && r.Destination.Mask == nil && r.Gateway == nil
 }
 
-func (r *Route) toTcpipRoute(id tcpip.NICID) tcpip.Route {
+func (r *Route) toTcpipRoute(id tcpip.NICID) (tcpip.Route, error) {
+	subnet, err := tcpip.NewSubnet(ipToAddress(r.Destination.IP), ipMaskToAddressMask(r.Destination.Mask))
+	if err != nil {
+		return tcpip.Route{}, err
+	}
 	return tcpip.Route{
-		Destination: ipToAddress(r.Destination),
+		Destination: subnet,
 		Gateway:     ipToAddress(r.Gateway),
-		Mask:        ipToAddressMask(net.IP(r.Mask)),
 		NIC:         id,
-	}
+	}, nil
 }
 
 // CreateLinksAndRoutes creates links and routes in a network stack.  It should
@@ -128,7 +130,11 @@ func (n *Network) CreateLinksAndRoutes(args *CreateLinksAndRoutesArgs, _ *struct
 
 		// Collect the routes from this link.
 		for _, r := range link.Routes {
-			routes = append(routes, r.toTcpipRoute(nicID))
+			route, err := r.toTcpipRoute(nicID)
+			if err != nil {
+				return err
+			}
+			routes = append(routes, route)
 		}
 	}
 
@@ -170,7 +176,11 @@ func (n *Network) CreateLinksAndRoutes(args *CreateLinksAndRoutesArgs, _ *struct
 
 		// Collect the routes from this link.
 		for _, r := range link.Routes {
-			routes = append(routes, r.toTcpipRoute(nicID))
+			route, err := r.toTcpipRoute(nicID)
+			if err != nil {
+				return err
+			}
+			routes = append(routes, route)
 		}
 	}
 
@@ -179,7 +189,11 @@ func (n *Network) CreateLinksAndRoutes(args *CreateLinksAndRoutesArgs, _ *struct
 		if !ok {
 			return fmt.Errorf("invalid interface name %q for default route", args.DefaultGateway.Name)
 		}
-		routes = append(routes, args.DefaultGateway.Route.toTcpipRoute(nicID))
+		route, err := args.DefaultGateway.Route.toTcpipRoute(nicID)
+		if err != nil {
+			return err
+		}
+		routes = append(routes, route)
 	}
 
 	log.Infof("Setting routes %+v", routes)
@@ -230,8 +244,8 @@ func ipToAddress(ip net.IP) tcpip.Address {
 	return addr
 }
 
-// ipToAddressMask converts IP to tcpip.AddressMask, ignoring the protocol.
-func ipToAddressMask(ip net.IP) tcpip.AddressMask {
-	_, addr := ipToAddressAndProto(ip)
-	return tcpip.AddressMask(addr)
+// ipMaskToAddressMask converts IPMask to tcpip.AddressMask, ignoring the
+// protocol.
+func ipMaskToAddressMask(ipMask net.IPMask) tcpip.AddressMask {
+	return tcpip.AddressMask(ipToAddress(net.IP(ipMask)))
 }
diff --git a/runsc/sandbox/network.go b/runsc/sandbox/network.go
index 333ffb65c..5634f0707 100644
--- a/runsc/sandbox/network.go
+++ b/runsc/sandbox/network.go
@@ -81,12 +81,17 @@ func createDefaultLoopbackInterface(conn *urpc.Client) error {
 		},
 		Routes: []boot.Route{
 			{
-				Destination: net.IP("\x7f\x00\x00\x00"),
-				Mask:        net.IPMask("\xff\x00\x00\x00"),
+				Destination: net.IPNet{
+
+					IP:   net.IPv4(0x7f, 0, 0, 0),
+					Mask: net.IPv4Mask(0xff, 0, 0, 0),
+				},
 			},
 			{
-				Destination: net.IPv6loopback,
-				Mask:        net.IPMask(strings.Repeat("\xff", 16)),
+				Destination: net.IPNet{
+					IP:   net.IPv6loopback,
+					Mask: net.IPMask(strings.Repeat("\xff", net.IPv6len)),
+				},
 			},
 		},
 	}
@@ -326,12 +331,13 @@ func loopbackLinks(iface net.Interface, addrs []net.Addr) ([]boot.LoopbackLink,
 		if !ok {
 			return nil, fmt.Errorf("address is not IPNet: %+v", addr)
 		}
+		dst := *ipNet
+		dst.IP = dst.IP.Mask(dst.Mask)
 		links = append(links, boot.LoopbackLink{
 			Name:      iface.Name,
 			Addresses: []net.IP{ipNet.IP},
 			Routes: []boot.Route{{
-				Destination: ipNet.IP.Mask(ipNet.Mask),
-				Mask:        ipNet.Mask,
+				Destination: dst,
 			}},
 		})
 	}
@@ -367,9 +373,11 @@ func routesForIface(iface net.Interface) ([]boot.Route, *boot.Route, error) {
 			}
 			// Create a catch all route to the gateway.
 			def = &boot.Route{
-				Destination: net.IPv4zero,
-				Mask:        net.IPMask(net.IPv4zero),
-				Gateway:     r.Gw,
+				Destination: net.IPNet{
+					IP:   net.IPv4zero,
+					Mask: net.IPMask(net.IPv4zero),
+				},
+				Gateway: r.Gw,
 			}
 			continue
 		}
@@ -377,9 +385,10 @@ func routesForIface(iface net.Interface) ([]boot.Route, *boot.Route, error) {
 			log.Warningf("IPv6 is not supported, skipping route: %v", r)
 			continue
 		}
+		dst := *r.Dst
+		dst.IP = dst.IP.Mask(dst.Mask)
 		routes = append(routes, boot.Route{
-			Destination: r.Dst.IP.Mask(r.Dst.Mask),
-			Mask:        r.Dst.Mask,
+			Destination: dst,
 			Gateway:     r.Gw,
 		})
 	}