From aa130f05d44611bb352b81c76b680e72a9573224 Mon Sep 17 00:00:00 2001
From: sbruens <sbruens@users.noreply.github.com>
Date: Wed, 8 Jan 2025 13:04:38 -0500
Subject: [PATCH] Split `Service` interface into outline-ss-server and Caddy
 interfaces.

---
 caddy/shadowsocks_handler.go  | 14 +++++++++-----
 cmd/outline-ss-server/main.go | 11 ++++++++++-
 service/shadowsocks.go        | 19 +++++++++++++------
 3 files changed, 32 insertions(+), 12 deletions(-)

diff --git a/caddy/shadowsocks_handler.go b/caddy/shadowsocks_handler.go
index b5edb283..c7247ad9 100644
--- a/caddy/shadowsocks_handler.go
+++ b/caddy/shadowsocks_handler.go
@@ -16,6 +16,7 @@ package caddy
 
 import (
 	"container/list"
+	"context"
 	"fmt"
 	"log/slog"
 	"net"
@@ -32,6 +33,11 @@ const serverUDPBufferSize = 64 * 1024
 
 const ssModuleName = "layer4.handlers.shadowsocks"
 
+type OutlineService interface {
+	HandleStream(ctx context.Context, conn transport.StreamConn)
+	HandleAssociation(conn net.Conn) error
+}
+
 func init() {
 	caddy.RegisterModule(ModuleRegistration{
 		ID:  ssModuleName,
@@ -48,7 +54,7 @@ type KeyConfig struct {
 type ShadowsocksHandler struct {
 	Keys []KeyConfig `json:"keys,omitempty"`
 
-	service outline.Service
+	service OutlineService
 	logger  *slog.Logger
 }
 
@@ -119,11 +125,9 @@ func (h *ShadowsocksHandler) Handle(cx *layer4.Connection, _ layer4.Handler) err
 	case transport.StreamConn:
 		h.service.HandleStream(cx.Context, conn)
 	case net.Conn:
-		assoc, err := h.service.NewPacketAssociation(conn)
-		if err != nil {
-			return fmt.Errorf("failed to handle association: %v", err)
+		if err := h.service.HandleAssociation(conn); err != nil {
+			return err
 		}
-		outline.HandleAssociation(conn, assoc)
 	default:
 		return fmt.Errorf("failed to handle unknown connection type: %t", conn)
 	}
diff --git a/cmd/outline-ss-server/main.go b/cmd/outline-ss-server/main.go
index d41bf685..602a5b3f 100644
--- a/cmd/outline-ss-server/main.go
+++ b/cmd/outline-ss-server/main.go
@@ -16,6 +16,7 @@ package main
 
 import (
 	"container/list"
+	"context"
 	"flag"
 	"fmt"
 	"log/slog"
@@ -27,6 +28,7 @@ import (
 	"syscall"
 	"time"
 
+	"github.com/Jigsaw-Code/outline-sdk/transport"
 	"github.com/Jigsaw-Code/outline-sdk/transport/shadowsocks"
 	"github.com/lmittmann/tint"
 	"github.com/prometheus/client_golang/prometheus"
@@ -60,6 +62,11 @@ func init() {
 	)
 }
 
+type OutlineService interface {
+	HandleStream(ctx context.Context, conn transport.StreamConn)
+	NewPacketAssociation(conn net.Conn) (service.PacketAssociation, error)
+}
+
 type OutlineServer struct {
 	stopConfig     func() error
 	lnManager      service.ListenerManager
@@ -223,6 +230,7 @@ func (s *OutlineServer) runConfig(config Config) (func() error, error) {
 				ciphers := service.NewCipherList()
 				ciphers.Update(cipherList)
 
+				var ssService OutlineService
 				ssService, err := service.NewShadowsocksService(
 					service.WithCiphers(ciphers),
 					service.WithMetrics(s.serviceMetrics),
@@ -250,7 +258,8 @@ func (s *OutlineServer) runConfig(config Config) (func() error, error) {
 				if err != nil {
 					return fmt.Errorf("failed to create cipher list from config: %v", err)
 				}
-				ssService, err := service.NewShadowsocksService(
+				var ssService OutlineService
+				ssService, err = service.NewShadowsocksService(
 					service.WithCiphers(ciphers),
 					service.WithMetrics(s.serviceMetrics),
 					service.WithReplayCache(&s.replayCache),
diff --git a/service/shadowsocks.go b/service/shadowsocks.go
index 062a7087..9137136d 100644
--- a/service/shadowsocks.go
+++ b/service/shadowsocks.go
@@ -16,6 +16,7 @@ package service
 
 import (
 	"context"
+	"fmt"
 	"log/slog"
 	"net"
 	"time"
@@ -41,11 +42,6 @@ type ServiceMetrics interface {
 	AddCipherSearch(proto string, accessKeyFound bool, timeToCipher time.Duration)
 }
 
-type Service interface {
-	HandleStream(ctx context.Context, conn transport.StreamConn)
-	NewPacketAssociation(conn net.Conn) (PacketAssociation, error)
-}
-
 // Option is a Shadowsocks service constructor option.
 type Option func(s *ssService)
 
@@ -63,7 +59,7 @@ type ssService struct {
 }
 
 // NewShadowsocksService creates a new Shadowsocks service.
-func NewShadowsocksService(opts ...Option) (Service, error) {
+func NewShadowsocksService(opts ...Option) (*ssService, error) {
 	s := &ssService{}
 
 	for _, opt := range opts {
@@ -146,6 +142,17 @@ func (s *ssService) HandleStream(ctx context.Context, conn transport.StreamConn)
 	s.sh.Handle(ctx, conn, metrics)
 }
 
+// HandleAssociation handles a Shadowsocks packet-based connection.
+func (s *ssService) HandleAssociation(conn net.Conn) error {
+	assoc, err := s.NewPacketAssociation(conn)
+	if err != nil {
+		return fmt.Errorf("failed to handle association: %v", err)
+	}
+	HandleAssociation(conn, assoc)
+	return nil
+}
+
+
 // NewPacketAssociation creates a new Shadowsocks packet-based association.
 func (s *ssService) NewPacketAssociation(conn net.Conn) (PacketAssociation, error) {
 	var metrics UDPAssociationMetrics