implement default outbound handler

app/proxyman/outbound/handler.go

@@ -0,0 +1,81 @@
+package outbound
+
+import (
+	"context"
+
+	"v2ray.com/core/app/proxyman"
+	"v2ray.com/core/common/errors"
+	"v2ray.com/core/common/net"
+	"v2ray.com/core/proxy"
+	"v2ray.com/core/transport/internet"
+)
+
+type Handler struct {
+	config           *proxyman.OutboundHandlerConfig
+	streamSettings   *proxyman.StreamSenderConfig
+	datagramSettings *proxyman.DatagramSenderConfig
+	proxy            proxy.OutboundHandler
+}
+
+func NewHandler(ctx context.Context, config *proxyman.OutboundHandlerConfig) (*Handler, error) {
+	h := &Handler{
+		config: config,
+	}
+	for _, rawSettings := range config.SenderSettings {
+		settings, err := rawSettings.GetInstance()
+		if err != nil {
+			return nil, err
+		}
+		switch ts := settings.(type) {
+		case *proxyman.StreamSenderConfig:
+			h.streamSettings = ts
+		case *proxyman.DatagramSenderConfig:
+			h.datagramSettings = ts
+		default:
+			return nil, errors.New("Proxyman|DefaultOutboundHandler: Unknown sender settings: ", rawSettings.Type)
+		}
+	}
+	proxyHandler, err := config.GetProxyHandler(proxy.ContextWithDialer(ctx, h))
+	if err != nil {
+		return nil, err
+	}
+
+	h.proxy = proxyHandler
+	return h, nil
+}
+
+func (h *Handler) Dial(ctx context.Context, destination net.Destination) (internet.Connection, error) {
+	switch destination.Network {
+	case net.Network_TCP:
+		return h.dialStream(ctx, destination)
+	case net.Network_UDP:
+		return h.dialDatagram(ctx, destination)
+	default:
+		panic("Proxyman|DefaultOutboundHandler: unexpected network.")
+	}
+}
+
+func (h *Handler) dialStream(ctx context.Context, destination net.Destination) (internet.Connection, error) {
+	var src net.Address
+	if h.streamSettings != nil {
+		src = h.streamSettings.Via.AsAddress()
+	}
+	var options internet.DialerOptions
+	if h.streamSettings != nil {
+		options.Proxy = h.streamSettings.ProxySettings
+		options.Stream = h.streamSettings.StreamSettings
+	}
+	return internet.Dial(src, destination, options)
+}
+
+func (h *Handler) dialDatagram(ctx context.Context, destination net.Destination) (internet.Connection, error) {
+	var src net.Address
+	if h.datagramSettings != nil {
+		src = h.datagramSettings.Via.AsAddress()
+	}
+	var options internet.DialerOptions
+	if h.datagramSettings != nil {
+		options.Proxy = h.datagramSettings.ProxySettings
+	}
+	return internet.Dial(src, destination, options)
+}