From a33e511c12d045b294946baba01a699763a346b2 Mon Sep 17 00:00:00 2001
From: Dreamacro <8615343+dreamacro@users.noreply.github.com>
Date: Fri, 15 Jul 2022 17:00:41 +0800
Subject: [PATCH] Fix: macOS udp find process should use unspecified fallback

---
 component/process/process_darwin.go | 44 ++++++++++++++++-------------
 1 file changed, 25 insertions(+), 19 deletions(-)

diff --git a/component/process/process_darwin.go b/component/process/process_darwin.go
index ef8f6e0e2..2728aad05 100644
--- a/component/process/process_darwin.go
+++ b/component/process/process_darwin.go
@@ -6,8 +6,6 @@ import (
 	"syscall"
 	"unsafe"
 
-	"github.com/Dreamacro/clash/common/nnip"
-
 	"golang.org/x/sys/unix"
 )
 
@@ -17,11 +15,7 @@ const (
 	proccallnumpidinfo  = 0x2
 )
 
-func resolveSocketByNetlink(network string, ip netip.Addr, srcPort int) (int32, int32, error) {
-	return 0, 0, ErrPlatformNotSupport
-}
-
-func findProcessName(network string, ip netip.Addr, port int) (int32, string, error) {
+func findProcessName(network string, ip netip.Addr, port int) (string, error) {
 	var spath string
 	switch network {
 	case TCP:
@@ -29,14 +23,14 @@ func findProcessName(network string, ip netip.Addr, port int) (int32, string, er
 	case UDP:
 		spath = "net.inet.udp.pcblist_n"
 	default:
-		return -1, "", ErrInvalidNetwork
+		return "", ErrInvalidNetwork
 	}
 
 	isIPv4 := ip.Is4()
 
 	value, err := syscall.Sysctl(spath)
 	if err != nil {
-		return -1, "", err
+		return "", err
 	}
 
 	buf := []byte(value)
@@ -50,6 +44,8 @@ func findProcessName(network string, ip netip.Addr, port int) (int32, string, er
 		// rup8(sizeof(xtcpcb_n))
 		itemSize += 208
 	}
+
+	var fallbackUDPProcess string
 	// skip the first xinpgen(24 bytes) block
 	for i := 24; i+itemSize <= len(buf); i += itemSize {
 		// offset of xinpcb_n and xsocket_n
@@ -63,29 +59,39 @@ func findProcessName(network string, ip netip.Addr, port int) (int32, string, er
 		// xinpcb_n.inp_vflag
 		flag := buf[inp+44]
 
-		var srcIP netip.Addr
+		var (
+			srcIP     netip.Addr
+			srcIsIPv4 bool
+		)
 		switch {
 		case flag&0x1 > 0 && isIPv4:
 			// ipv4
-			srcIP = nnip.IpToAddr(buf[inp+76 : inp+80])
+			srcIP, _ = netip.AddrFromSlice(buf[inp+76 : inp+80])
+			srcIsIPv4 = true
 		case flag&0x2 > 0 && !isIPv4:
 			// ipv6
-			srcIP = nnip.IpToAddr(buf[inp+64 : inp+80])
+			srcIP, _ = netip.AddrFromSlice(buf[inp+64 : inp+80])
 		default:
 			continue
 		}
 
-		if ip != srcIP && (network == TCP || !srcIP.IsUnspecified()) {
-			continue
+		if ip == srcIP {
+			// xsocket_n.so_last_pid
+			pid := readNativeUint32(buf[so+68 : so+72])
+			return getExecPathFromPID(pid)
 		}
 
-		// xsocket_n.so_last_pid
-		pid := readNativeUint32(buf[so+68 : so+72])
-		pp, err := getExecPathFromPID(pid)
-		return -1, pp, err
+		// udp packet connection may be not equal with srcIP
+		if network == UDP && srcIP.IsUnspecified() && isIPv4 == srcIsIPv4 {
+			fallbackUDPProcess, _ = getExecPathFromPID(readNativeUint32(buf[so+68 : so+72]))
+		}
 	}
 
-	return -1, "", ErrNotFound
+	if network == UDP && fallbackUDPProcess != "" {
+		return fallbackUDPProcess, nil
+	}
+
+	return "", ErrNotFound
 }
 
 func getExecPathFromPID(pid uint32) (string, error) {