init

internal/route/route_linux.go

@@ -0,0 +1,47 @@
+//go:build !darwin
+
+package route
+
+import (
+	"fmt"
+	"os/exec"
+	"strings"
+)
+
+func addRoute(cidr, iface string) error {
+	return runCmd("ip", "route", "add", cidr, "dev", iface)
+}
+
+func deleteRoute(cidr, iface string) error {
+	return runCmd("ip", "route", "del", cidr, "dev", iface)
+}
+
+func addRouteVia(cidr, gateway string) error {
+	return runCmd("ip", "route", "add", cidr, "via", gateway)
+}
+
+func deleteRouteVia(cidr, gateway string) error {
+	return runCmd("ip", "route", "del", cidr, "via", gateway)
+}
+
+func defaultGateway() (string, error) {
+	out, err := exec.Command("ip", "route", "show", "default").Output()
+	if err != nil {
+		return "", err
+	}
+	fields := strings.Fields(strings.TrimSpace(string(out)))
+	for i, f := range fields {
+		if f == "via" && i+1 < len(fields) {
+			return fields[i+1], nil
+		}
+	}
+	return "", fmt.Errorf("no default gateway found")
+}
+
+func runCmd(name string, args ...string) error {
+	cmd := exec.Command(name, args...)
+	if out, err := cmd.CombinedOutput(); err != nil {
+		return fmt.Errorf("%s %s: %w (%s)", name, strings.Join(args, " "), err, strings.TrimSpace(string(out)))
+	}
+	return nil
+}