Firewall added & some fixes

network/vlan.go

@@ -0,0 +1,80 @@
+package network
+
+import (
+	"fmt"
+	"os"
+	"os/exec"
+	"strconv"
+	"strings"
+)
+
+// IsVLAN reports whether name is a VLAN interface (e.g. "eth0.100").
+func IsVLAN(name string) bool {
+	idx := strings.LastIndex(name, ".")
+	if idx <= 0 {
+		return false
+	}
+	suffix := name[idx+1:]
+	if suffix == "" {
+		return false
+	}
+	_, err := strconv.Atoi(suffix)
+	return err == nil
+}
+
+// VLANParent returns the parent interface (e.g. "eth0.100" → "eth0").
+func VLANParent(name string) string {
+	idx := strings.LastIndex(name, ".")
+	if idx < 0 {
+		return ""
+	}
+	return name[:idx]
+}
+
+// VLANId returns the VLAN ID (e.g. "eth0.100" → 100).
+func VLANId(name string) int {
+	idx := strings.LastIndex(name, ".")
+	if idx < 0 {
+		return 0
+	}
+	id, _ := strconv.Atoi(name[idx+1:])
+	return id
+}
+
+// EnsureVLANExists creates the VLAN interface in the kernel if it doesn't exist.
+func EnsureVLANExists(name string) error {
+	if _, err := os.Stat("/sys/class/net/" + name); err == nil {
+		return nil
+	}
+	parent := VLANParent(name)
+	id := VLANId(name)
+	if parent == "" || id == 0 {
+		return fmt.Errorf("invalid VLAN name: %s", name)
+	}
+	out, err := exec.Command("ip", "link", "add", "link", parent,
+		"name", name, "type", "vlan", "id", strconv.Itoa(id)).CombinedOutput()
+	if err != nil {
+		return fmt.Errorf("ip link add %s: %s", name, strings.TrimSpace(string(out)))
+	}
+	return nil
+}
+
+// DeleteVLAN brings down and removes a VLAN interface and its /etc/network/interfaces stanza.
+func DeleteVLAN(name string) error {
+	_ = IfDown(name)
+	if _, err := os.Stat("/sys/class/net/" + name); err == nil {
+		out, err2 := exec.Command("ip", "link", "delete", name).CombinedOutput()
+		if err2 != nil {
+			return fmt.Errorf("ip link delete %s: %s", name, strings.TrimSpace(string(out)))
+		}
+	}
+	configs, err := ParseConfig()
+	if err != nil {
+		return err
+	}
+	if _, ok := configs[name]; ok {
+		delete(configs, name)
+		return WriteConfig(configs)
+	}
+	return nil
+}