fix(ss): address review findings for PR #96 — nil guards, resource leaks, dead code

- Bump go-shadowsocks2 to v0.1.3 (new API symbols)
- Return error instead of nil when Target() is empty in TCP handler
- Reset wbuf unconditionally on write error to prevent unbounded growth
- Add nil guard on targetAddr before WriteTo to prevent panic
- Remove duplicate NewClientConfig call and dead ClientConfig literal
- Remove unused noDelay metadata field
- Fix buffer-size guard to catch negative values (len(b)==0 → bufSize<=0)
- Add address context to parse/session error messages

connector/ss/metadata.go

@@ -10,19 +10,16 @@ import (
 type metadata struct {
 	key            string
 	connectTimeout time.Duration
-	noDelay        bool
 }
 
 func (c *ssConnector) parseMetadata(md mdata.Metadata) (err error) {
 	const (
 		key            = "key"
 		connectTimeout = "timeout"
-		noDelay        = "nodelay"
 	)
 
 	c.md.key = mdutil.GetString(md, key)
 	c.md.connectTimeout = mdutil.GetDuration(md, connectTimeout)
-	c.md.noDelay = mdutil.GetBool(md, noDelay)
 
 	return
 }

connector/ss/udp/connector.go

@@ -58,13 +58,8 @@ func (c *ssuConnector) Init(md md.Metadata) (err error) {
 	}
 	clientConfig.UDPTimeout = time.Minute
 
-	tcpClientConfig, err := utils.NewClientConfig(method, password)
-	if err != nil {
-		return err
-	}
-
 	c.clientCfg = clientConfig
-	c.tcpClient = core.NewTCPClient(tcpClientConfig)
+	c.tcpClient = core.NewTCPClient(clientConfig)
 
 	return
 }
@@ -98,15 +93,11 @@ func (c *ssuConnector) Connect(ctx context.Context, conn net.Conn, network, addr
 	}
 	serverAddr, err := netip.ParseAddrPort(conn.RemoteAddr().String())
 	if err != nil {
-		return nil, err
+		return nil, fmt.Errorf("ss: parse remote addr %q: %w", conn.RemoteAddr().String(), err)
 	}
 	clientCfg := c.clientCfg
 	clientCfg.ServerAddr = serverAddr
-	client := core.NewUDPClient(core.ClientConfig{
-		Cipher:     clientCfg.Cipher,
-		ServerAddr: serverAddr,
-		UDPTimeout: time.Minute,
-	})
+	client := core.NewUDPClient(clientCfg)
 	if err := client.Init(); err != nil {
 		return nil, err
 	}

go.mod

@@ -8,7 +8,7 @@ require (
 	github.com/gin-contrib/cors v1.7.2
 	github.com/gin-gonic/gin v1.10.1
 	github.com/go-gost/core v0.4.0
-	github.com/go-gost/go-shadowsocks2 v0.1.2
+	github.com/go-gost/go-shadowsocks2 v0.1.3
 	github.com/go-gost/gosocks4 v0.1.0
 	github.com/go-gost/gosocks5 v0.5.0
 	github.com/go-gost/plugin v0.3.0

go.sum

@@ -51,8 +51,8 @@ github.com/gin-gonic/gin v1.10.1 h1:T0ujvqyCSqRopADpgPgiTT63DUQVSfojyME59Ei63pQ=
 github.com/gin-gonic/gin v1.10.1/go.mod h1:4PMNQiOhvDRa013RKVbsiNwoyezlm2rm0uX/T7kzp5Y=
 github.com/go-gost/core v0.4.0 h1:jLuIMO7ZMJX/BDCYLrYXAmIykT+HkqEuzaTeLMdrY1c=
 github.com/go-gost/core v0.4.0/go.mod h1:WGI43jOka7FAsSAwi/fSMaqxdR+E339ycb4NBGlFr6A=
-github.com/go-gost/go-shadowsocks2 v0.1.2 h1:qgTUQS6aCGzsFArjiKjLP0a7zEVtEYVCRVc5LjOsaVk=
-github.com/go-gost/go-shadowsocks2 v0.1.2/go.mod h1:866zFNNI3He6Wef1M/IvAjTal74WhcfKfBgRpTlkKys=
+github.com/go-gost/go-shadowsocks2 v0.1.3 h1:6CUZLp+mTWXnKP2aK8/Z9ZP+ERMX9gSbywmPu4kGX/A=
+github.com/go-gost/go-shadowsocks2 v0.1.3/go.mod h1:866zFNNI3He6Wef1M/IvAjTal74WhcfKfBgRpTlkKys=
 github.com/go-gost/gosocks4 v0.1.0 h1:eAzev6qw4fzkFQKC9uCHLVNnnPdHyqCggbnfNN80Pmk=
 github.com/go-gost/gosocks4 v0.1.0/go.mod h1:hzVjwijJuZR1pp3GqpTj+AKcSGrx68RlWTrQMFMYBP0=
 github.com/go-gost/gosocks5 v0.5.0 h1:YE37l1MJwde8diIQdynStqogMotG5enoTdborhA5yic=

handler/ss/handler.go

@@ -149,7 +149,7 @@ func (h *ssHandler) Handle(ctx context.Context, conn net.Conn, opts ...handler.H
 		target = tc.Target()
 	}
 	if len(target) == 0 {
-		return
+		return errors.New("ss: target not available")
 	}
 	conn = wrappedConn
 

handler/ss/udp/handler.go

@@ -4,6 +4,7 @@ import (
 	"bytes"
 	"context"
 	"errors"
+	"fmt"
 	"net"
 	"sync"
 	"time"
@@ -191,7 +192,7 @@ func (h *ssuHandler) relayPacketUDP(ctx context.Context, src net.PacketConn, ro
 			TargetAddr() net.Addr
 		})
 		if !ok {
-			return errors.New("ss: missing udp session context")
+			return fmt.Errorf("ss: missing udp session context for addr %v", addr)
 		}
 
 		targetAddr := ctxAddr.TargetAddr()
@@ -204,9 +205,13 @@ func (h *ssuHandler) relayPacketUDP(ctx context.Context, src net.PacketConn, ro
 			return nil
 		}
 
+		if targetAddr == nil {
+			return errors.New("ss: target address not available")
+		}
+
 		session := ctxAddr.Session()
 		if session == nil {
-			return errors.New("ss: udp session not found")
+			return fmt.Errorf("ss: udp session not found for addr %v", addr)
 		}
 
 		dstConn, err := h.packetConnForSession(ctx, src, session, ro, log)
@@ -255,10 +260,11 @@ func (h *ssuHandler) packetConnForSession(ctx context.Context, src net.PacketCon
 			h.connMap.Delete(session.Hash())
 		}()
 
-		b := make([]byte, h.md.udpBufferSize)
-		if len(b) == 0 {
-			b = make([]byte, defaultBufferSize)
+		bufSize := h.md.udpBufferSize
+		if bufSize <= 0 {
+			bufSize = defaultBufferSize
 		}
+		b := make([]byte, bufSize)
 
 		for {
 			n, raddr, err := cc.ReadFrom(b)

internal/util/ss/ss.go

@@ -36,10 +36,7 @@ func (c *shadowConn) Write(b []byte) (n int, err error) {
 		c.wbuf.Write(b) // append the data to the cached header
 		written, err := c.Conn.Write(c.wbuf.Bytes())
 		if err != nil {
-			// If short write, keep unwritten bytes
-			if written > 0 && written < c.wbuf.Len() {
-				c.wbuf.Next(written)
-			}
+			c.wbuf.Reset()
 			return written, err
 		}
 		c.wbuf.Reset()