daemon: use per-interface features

Signed-off-by: Steffen Vogel <post@steffenvogel.de>

pkg/daemon/feature/epdisc/proxy/proxy_user.go

@@ -0,0 +1,83 @@
+package proxy
+
+import (
+	"errors"
+	"fmt"
+	"io"
+	"net"
+
+	"github.com/pion/ice/v2"
+	"go.uber.org/zap"
+
+	"github.com/stv0g/cunicu/pkg/wg"
+
+	protoepdisc "github.com/stv0g/cunicu/pkg/proto/feature/epdisc"
+)
+
+type UserBindProxy struct {
+	bind     *wg.UserBind
+	endpoint *wg.UserEndpoint
+
+	conn *ice.Conn
+
+	logger *zap.Logger
+}
+
+func NewUserBindProxy(bind *wg.UserBind) (*UserBindProxy, error) {
+	return &UserBindProxy{
+		bind:   bind,
+		logger: zap.L().Named("proxy").With(zap.String("type", "user-bind")),
+	}, nil
+}
+
+func (p *UserBindProxy) Close() error {
+	return nil
+}
+
+func (p *UserBindProxy) UpdateCandidatePair(cp *ice.CandidatePair, conn *ice.Conn) (*net.UDPAddr, error) {
+	var err error
+
+	p.logger.Debug("Forwarding via in-process bind")
+
+	ep := &net.UDPAddr{
+		IP:   net.ParseIP(cp.Remote.Address()),
+		Port: cp.Remote.Port(),
+	}
+
+	p.endpoint, err = p.bind.UpdateEndpoint(ep, conn)
+	if err != nil {
+		return nil, fmt.Errorf("failed to update endpoint: %w", err)
+	}
+
+	if conn != p.conn {
+		go p.read(conn)
+	}
+
+	return ep, nil
+}
+
+func (p *UserBindProxy) read(conn *ice.Conn) {
+	p.conn = conn
+
+	for {
+		buf := make([]byte, maxSegmentSize)
+
+		n, err := p.conn.Read(buf)
+		if err != nil {
+			if errors.Is(err, ice.ErrClosed) || errors.Is(err, io.EOF) {
+				return
+			}
+
+			p.logger.Error("Failed to read from ICE connection", zap.Error(err))
+			continue
+		}
+
+		if err := p.bind.OnData(buf[:n], p.endpoint); err != nil {
+			p.logger.Error("Failed to pass data to bind", zap.Error(err))
+		}
+	}
+}
+
+func (p *UserBindProxy) Type() protoepdisc.ProxyType {
+	return protoepdisc.ProxyType_USER_BIND
+}