From 6a0987c52ae4f108b667ffcf72c280ca8fe9dce9 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E4=B8=96=E7=95=8C?= <i@sekai.icu>
Date: Thu, 7 Jul 2022 21:39:44 +0800
Subject: [PATCH] Minor fixes

---
 common/cond.go                | 10 ++++++++++
 common/control/bind_linux.go  |  4 ++--
 common/control/mark_linux.go  |  4 ++--
 common/control/reuse_linux.go |  6 +++---
 protocol/socks/handshake.go   |  5 +++--
 5 files changed, 20 insertions(+), 9 deletions(-)

diff --git a/common/cond.go b/common/cond.go
index 4e60848..a655657 100644
--- a/common/cond.go
+++ b/common/cond.go
@@ -92,6 +92,16 @@ func FilterNotDefault[T comparable](arr []T) []T {
 	})
 }
 
+func FilterIndexed[T any](arr []T, block func(index int, it T) bool) []T {
+	var retArr []T
+	for i, it := range arr {
+		if block(i, it) {
+			retArr = append(retArr, it)
+		}
+	}
+	return retArr
+}
+
 func Find[T any](arr []T, block func(it T) bool) T {
 	for _, it := range arr {
 		if block(it) {
diff --git a/common/control/bind_linux.go b/common/control/bind_linux.go
index ebc5681..883acca 100644
--- a/common/control/bind_linux.go
+++ b/common/control/bind_linux.go
@@ -3,7 +3,7 @@ package control
 import (
 	"syscall"
 
-	"github.com/sagernet/sing/common"
+	E "github.com/sagernet/sing/common/exceptions"
 )
 
 func BindToInterface(interfaceName string) Func {
@@ -12,6 +12,6 @@ func BindToInterface(interfaceName string) Func {
 		err := conn.Control(func(fd uintptr) {
 			innerErr = syscall.BindToDevice(int(fd), interfaceName)
 		})
-		return common.AnyError(innerErr, err)
+		return E.Errors(innerErr, err)
 	}
 }
diff --git a/common/control/mark_linux.go b/common/control/mark_linux.go
index d217371..040ebf7 100644
--- a/common/control/mark_linux.go
+++ b/common/control/mark_linux.go
@@ -3,7 +3,7 @@ package control
 import (
 	"syscall"
 
-	"github.com/sagernet/sing/common"
+	E "github.com/sagernet/sing/common/exceptions"
 )
 
 func RoutingMark(mark int) Func {
@@ -12,6 +12,6 @@ func RoutingMark(mark int) Func {
 		err := conn.Control(func(fd uintptr) {
 			innerErr = syscall.SetsockoptInt(int(fd), syscall.SOL_SOCKET, syscall.SO_MARK, mark)
 		})
-		return common.AnyError(innerErr, err)
+		return E.Errors(innerErr, err)
 	}
 }
diff --git a/common/control/reuse_linux.go b/common/control/reuse_linux.go
index d7e2281..3d92db1 100644
--- a/common/control/reuse_linux.go
+++ b/common/control/reuse_linux.go
@@ -3,7 +3,7 @@ package control
 import (
 	"syscall"
 
-	"github.com/sagernet/sing/common"
+	E "github.com/sagernet/sing/common/exceptions"
 )
 
 func ReuseAddr() Func {
@@ -11,11 +11,11 @@ func ReuseAddr() Func {
 		var innerErr error
 		err := conn.Control(func(fd uintptr) {
 			const SO_REUSEPORT = 0xf
-			innerErr = common.AnyError(
+			innerErr = E.Errors(
 				syscall.SetsockoptInt(int(fd), syscall.SOL_SOCKET, syscall.SO_REUSEADDR, 1),
 				syscall.SetsockoptInt(int(fd), syscall.SOL_SOCKET, SO_REUSEPORT, 1),
 			)
 		})
-		return common.AnyError(innerErr, err)
+		return E.Errors(innerErr, err)
 	}
 }
diff --git a/protocol/socks/handshake.go b/protocol/socks/handshake.go
index 3202bb5..98715a2 100644
--- a/protocol/socks/handshake.go
+++ b/protocol/socks/handshake.go
@@ -202,7 +202,8 @@ func HandleConnection0(ctx context.Context, conn net.Conn, version byte, authent
 			metadata.Destination = request.Destination
 			return handler.NewConnection(ctx, conn, metadata)
 		case socks5.CommandUDPAssociate:
-			udpConn, err := net.ListenUDP(M.NetworkFromNetAddr("udp", M.AddrFromNetAddr(conn.LocalAddr())), net.UDPAddrFromAddrPort(netip.AddrPortFrom(M.AddrFromNetAddr(conn.LocalAddr()), 0)))
+			var udpConn *net.UDPConn
+			udpConn, err = net.ListenUDP(M.NetworkFromNetAddr("udp", M.AddrFromNetAddr(conn.LocalAddr())), net.UDPAddrFromAddrPort(netip.AddrPortFrom(M.AddrFromNetAddr(conn.LocalAddr()), 0)))
 			if err != nil {
 				return err
 			}
@@ -224,7 +225,7 @@ func HandleConnection0(ctx context.Context, conn net.Conn, version byte, authent
 				close(done)
 			}()
 			err = common.Error(io.Copy(io.Discard, conn))
-			return E.New(innerError, err)
+			return E.Errors(innerError, err)
 		default:
 			err = socks5.WriteResponse(conn, socks5.Response{
 				ReplyCode: socks5.ReplyCodeUnsupported,