Use simulated dual-stack binds when using WSL

Resolves a WSL problem where traffic from only one stack is relayed

Signed-off-by: Jason T. Greene <jason.greene@redhat.com>

1 files changed, 37 insertions, 0 deletions

diff --git a/cmd/rootlessport/wsl.go b/cmd/rootlessport/wsl.go
new file mode 100644
index 000000000..c1e67ba87
--- /dev/null
+++ b/cmd/rootlessport/wsl.go
@@ -0,0 +1,37 @@
+package main
+
+import (
+	"net"
+	"strings"
+
+	"github.com/containers/common/pkg/machine"
+	rkport "github.com/rootless-containers/rootlesskit/pkg/port"
+)
+
+// WSL machines do not relay ipv4 traffic to dual-stack ports, simulate instead
+func splitDualStackSpecIfWsl(spec rkport.Spec) []rkport.Spec {
+	specs := []rkport.Spec{spec}
+	protocol := spec.Proto
+	if machine.MachineHostType() != machine.Wsl || strings.HasSuffix(protocol, "4") || strings.HasSuffix(protocol, "6") {
+		return specs
+	}
+
+	ip := net.ParseIP(spec.ParentIP)
+	splitLoopback := ip.IsLoopback() && ip.To4() == nil
+	// Map ::1 and 0.0.0.0/:: to ipv4 + ipv6 to simulate dual-stack
+	if ip.IsUnspecified() || splitLoopback {
+		specs = append(specs, spec)
+		specs[0].Proto = protocol + "4"
+		specs[1].Proto = protocol + "6"
+		if splitLoopback {
+			// Hacky, but we will only have one ipv4 loopback with WSL config
+			specs[0].ParentIP = "127.0.0.1"
+		}
+		if ip.IsUnspecified() {
+			specs[0].ParentIP = "0.0.0.0"
+			specs[1].ParentIP = "::"
+		}
+	}
+
+	return specs
+}