Merge release-20211011.0-39-g207221ffb (automated)

1 files changed, 9 insertions, 0 deletions

diff --git a/pkg/tcpip/header/ipv4.go b/pkg/tcpip/header/ipv4.go
index dcc549c7b..7baaf0d17 100644
--- a/pkg/tcpip/header/ipv4.go
+++ b/pkg/tcpip/header/ipv4.go
@@ -208,6 +208,15 @@ var IPv4EmptySubnet = func() tcpip.Subnet {
 	return subnet
 }()
 
+// IPv4LoopbackSubnet is the loopback subnet for IPv4.
+var IPv4LoopbackSubnet = func() tcpip.Subnet {
+	subnet, err := tcpip.NewSubnet(tcpip.Address("\x7f\x00\x00\x00"), tcpip.AddressMask("\xff\x00\x00\x00"))
+	if err != nil {
+		panic(err)
+	}
+	return subnet
+}()
+
 // IPVersion returns the version of IP used in the given packet. It returns -1
 // if the packet is not large enough to contain the version field.
 func IPVersion(b []byte) int {