Create cli/internal package

cli/internal/vpn/vpn.go

@@ -0,0 +1,101 @@
+package vpn
+
+import (
+	"fmt"
+	"net"
+	"time"
+
+	wgquick "github.com/nmiculinic/wg-quick-go"
+	"golang.zx2c4.com/wireguard/wgctrl/wgtypes"
+)
+
+const (
+	interfaceName = "wg0"
+	wireguardPort = 51820
+)
+
+type ConfigHandler struct {
+	up func(cfg *wgquick.Config, iface string) error
+}
+
+func NewConfigHandler() *ConfigHandler {
+	return &ConfigHandler{up: wgquick.Up}
+}
+
+func (h *ConfigHandler) Create(coordinatorPubKey, coordinatorPubIP, clientPrivKey, clientVPNIP string, mtu int) (*wgquick.Config, error) {
+	return NewWGQuickConfig(coordinatorPubKey, coordinatorPubIP, clientPrivKey, clientVPNIP, mtu)
+}
+
+// Apply applies the generated WireGuard quick config.
+func (h *ConfigHandler) Apply(conf *wgquick.Config) error {
+	return h.up(conf, interfaceName)
+}
+
+// GetBytes returns the the bytes of the config.
+func (h *ConfigHandler) Marshal(conf *wgquick.Config) ([]byte, error) {
+	data, err := conf.MarshalText()
+	if err != nil {
+		return nil, fmt.Errorf("marshal wg-quick config: %w", err)
+	}
+	return data, nil
+}
+
+// newConfig creates a new WireGuard configuration.
+func newConfig(coordinatorPubKey, coordinatorPubIP, clientPrivKey string) (wgtypes.Config, error) {
+	_, allowedIPs, err := net.ParseCIDR("10.118.0.1/32")
+	if err != nil {
+		return wgtypes.Config{}, fmt.Errorf("parsing CIDR: %w", err)
+	}
+
+	coordinatorPubKeyParsed, err := wgtypes.ParseKey(coordinatorPubKey)
+	if err != nil {
+		return wgtypes.Config{}, fmt.Errorf("parsing coordinator public key: %w", err)
+	}
+
+	var endpoint *net.UDPAddr
+	if ip := net.ParseIP(coordinatorPubIP); ip != nil {
+		endpoint = &net.UDPAddr{IP: ip, Port: wireguardPort}
+	} else {
+		endpoint = nil
+	}
+	clientPrivKeyParsed, err := wgtypes.ParseKey(clientPrivKey)
+	if err != nil {
+		return wgtypes.Config{}, fmt.Errorf("parsing client private key: %w", err)
+	}
+	listenPort := wireguardPort
+
+	keepAlive := 10 * time.Second
+	return wgtypes.Config{
+		PrivateKey:   &clientPrivKeyParsed,
+		ListenPort:   &listenPort,
+		ReplacePeers: false,
+		Peers: []wgtypes.PeerConfig{
+			{
+				PublicKey:                   coordinatorPubKeyParsed,
+				UpdateOnly:                  false,
+				Endpoint:                    endpoint,
+				AllowedIPs:                  []net.IPNet{*allowedIPs},
+				PersistentKeepaliveInterval: &keepAlive,
+			},
+		},
+	}, nil
+}
+
+// NewWGQuickConfig create a new WireGuard wg-quick configuration file and mashals it to bytes.
+func NewWGQuickConfig(coordinatorPubKey, coordinatorPubIP, clientPrivKey, clientVPNIP string, mtu int) (*wgquick.Config, error) {
+	config, err := newConfig(coordinatorPubKey, coordinatorPubIP, clientPrivKey)
+	if err != nil {
+		return nil, err
+	}
+
+	clientIP := net.ParseIP(clientVPNIP)
+	if clientIP == nil {
+		return nil, fmt.Errorf("invalid client vpn ip '%s'", clientVPNIP)
+	}
+	quickfile := wgquick.Config{
+		Config:  config,
+		Address: []net.IPNet{{IP: clientIP, Mask: []byte{255, 255, 0, 0}}},
+		MTU:     mtu,
+	}
+	return &quickfile, nil
+}